equilibrium 1 eqllllbl.. - wikispacespacket... · eqllllb"l.. equilibrium 1 ~ equilibrium: the...

18
Equilibrium 1 Eqllllb"l .. Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow between reactants and products) -4 .,.. AB ArB';;: A8 1. General Information A. Can ONLY occur in a closed system B. Equilibrium is dynamic: there is constant interaction between reactants and products, but the quantities of the reactants and products are usually not equal- only the rate of change Example: Rate of evaporation and condensation of water in a closed jar is at equilibrium BUT the amount of water occurring as liquid and vapor are NOT equal .. L. ) ("') - .8 .. - 00" ')0 C) 2. Physical Equilibrium A. Phase Equilibrium 1. Solid -liquid equilibrium: The rate of melting = the rate of freezing H-JO(s) 11)0(1) 2. Liquid - gas equilibrium: The rate of evaporation = the rate of condensation <= H

Upload: vuongdien

Post on 07-Mar-2018

225 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Equilibrium 1

Eqllllbl ~ Equilibrium the forward and reverse reactions occur at the same rate

(represented by a double arrow between reactants and products)

-4 egt~ AB ~ ArB A8 1 General Information

A Can ONLY occur in a closed system

B Equilibrium is dynamic there is constant interaction between reactants and

products but the quantities of the reactants and products are usually not

equal- only the rate of change

Example Rate ofevaporation and condensation ofwater in a closed jar is at

equilibrium BUT the amount ofwater occurring as liquid and vapor

are NOT equal

~

L) () shy8 -00)0 C)

2 Physical Equilibrium

A Phase Equilibrium

1 Solid -liquid equilibrium The rate ofmelting =the rate of freezing

H-JO(s) ~ 11)0(1)

2 Liquid - gas equilibrium The rate ofevaporation = the rate of

condensation

~ ~fJO(t) lt= H ~O(3)

Equilibrium 2

B Solution Equilibrium (NOTE MUST BE SATURATED SOLUTIONS)

1 Gases in Liquids The rate of gas dissolving in a liquid =the rate of gas ~

escaping the liquid

2 Solids in Liquids the rate ofdissolving = the rate ofcrystallization S(rLrot-t~

ox) sed CO)(9) ~ (OJ(Q1) J t) tNeJu AIcitS) ~ N tashybull j t- I e- DI5solveJ

3 Chemical Equilibrium tlaquo2laquo ()1lt- u J1ltltgt I

A The point at which the concentrations of all reactants and products cease to

change with time

B The rate at which reactants are making products equals the rate at which

products are making reactants

C When reactants are first mixed only the forward reaction occurs Over time as

products are formed the rate ofthe forward reaction slows as reactants are

used up (concentration decreases) and the reverse reaction speeds up because

the concentration ofproducts increases This occurs until the rates of the two

reactions are equal ~iB~AB

Forward Reaction

~~

Time ~

5V1lh4 ~ At-B)

- j lt I lt J S )~n~ _J i - -( ie rt q ~~tlf4 v~d ()P

Reverse Reaction

Time

fyenJ-I~ no 48 I

rctif lMlto KS q lt + ( oj iJC ~ lt tOf Yh I

Equilibrium

Time

fiyW4 r d f rC liC ~)e (rltU) Pee Dyr4Z

euroraJ ~

Equilibrium 3

4 Law ofMass Action

A Founded by Maximilian Goldberg and Peter Waage in 1864

B Shows the relationship between the concentration of the reactants and the

concentration of the products for a reaction at equilibrium

C aka Equilibrium Expression 41 0 3 +6Noce ~ JA(J3 t 3NaO 1 Given the hypothetical equation aA + bB ~ cC + dD

a Lower case letters represent the coefficient ( ofmoles)

b Upper case letters represent the compound

2 Kc =K =[Ct[Dt Products over reactants ~ = fA 1J~l-fJJ()ffJJ3 ~ q [At[Bt [J)~~J [N~(JJo

a The square brackets indicate the equilibrium concentration

b The exponents are the coefficient$

c Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

3 Kc =Keq = equilibrium constant

a-tm ttnitamp vnfrs ampzt~4 (Yv 1It t(ul~

b independent ofstarting reactant concentrations

4 Interpreting the magnitude ofKeq I

a When Keq gt 1 the reaction is product favored PYC i cc wCr ltt~[()

th- r u(f 1fIb When Keq lt 1 the reaction is reactant favored

5 Calcolatmg Keq

A If all equilibrium concentrations are known simply plug numbers into the Keq

expression and solve

B Ifall concentrations are not known - use ICE box method

I = initial concentrations C =change in concentrations E =concentrations at equilibrium

1 The change in concentration of reactants is negative 2 The change in concentration of the products is positive

3 The change in concentration corresponds to the mole ratios (coeffs)

___

Narne A1Sllrlt-Y IavEQUILIBRIUM CONSTANT (K)

Write the expression for the equilibrium constant K for the reactions below

1 N2(g) + 3H 2(g) ~ 2NH3(g)

~Ke [ NIi ~ ] fJ MM-MPYmiddoto [iJJ ][H]3

2 2KCIOis) ~ 2KCI(s) + 30 (g)2

MMMtJdcft6 = f5aJtO)jJ [O]s P4f7(

~ SolidS d~~

3 H 0(I) ~ H+(aq) + OH-(aq)2

111I Jl

Ke = [WJf2j-r LH][OH]cc

~ ff~~ (tJUA

4 2CO(g) + 02(g) ~ 2C02(g)

n f--1

K~ -= [COJ ] -1t ~-

[COJ~ [0)J 1

5 Li2C0

3(S) ~ 2Li+(aq) + C03-2(aq)

I iCU J gt[cO~-J = [LJ lt] J [CO~-] f1 1-11keD 0 -[L~

501lds d~L~

bull

1_amp_ llII~LL 70 CCllndn Irtinnni Fnir Inc

4

__ ___

Name ________CALCULATIONS USING lIiE EQUILIBRIUM CONSTANT

Using the equilibrium constant expressions you determined on page 79 calculate the value of K when

~

1 [NH3J = 00100 M [N2] = 00200 M [H2] = 00200 M

kit - fOIJ~ ~ Prou ismiddot lfJY(J( [o~r[9JJ b~S tshy

2 [deg21 = 00500 M

Kt6 J~(OS] )C )lt 10 -I f~ ~itdalt-tgt ftr VdY(J CK~

B [H+) = 1 X 108 M [OH] = 1 X 106 M

K -= 010 R)DXlJtJ D-~ W ~

~

qa l ~lt (qIJortd

4 [CO] = 20 M [02] = 15 M [C02] = 30 M

kt~ - [ - J) _I

() r L - 5 ML-~J I ~J

iou c JrVdY(c

5 [Li+] = 02 M [C032] = 01 M

YIb shy [ ~] l[J -= (JO L1 M1 shy d~ tf ( 1tLl~ 1 ( f (

I 0( 1 _bullbull _Lt I _t~ I ~ _

c[ Eo) 11gt~e-fru

Equilibrium 4 aJ 71 ~i 01

-7C Practice 1

l

IS + shy

l

dhO shy

middot~d _

lrti~ shy~ shy

A mixture of 500xlO-3 mole ofH2 and 1000xlO-2 moles of12 is placed in a

5000L container at 448degC and allowed to come to equilibrium Analysis

of the equilibrium mixture shows that the concentration ofHI is 187xlOmiddot3 M

Calculate Keq at 448degC for the reaction ~li eyruwgt

I ~

J __ r~p( (gt lt -1 1v

U~ JIVey mfo +0 r-t Molan Ius tv sfart fJ III -fu tx)Xes

r-1 d ~ QJ25M ~ 001 N 51shy

1 0 (fI(P_ - DOd H ~- ~J 5L F-d CrJ tlJhaf yfJlA knew tcbozmiddotd )y711) vmiddot--tr( )) Vvt)( (

- 1tv --ll 0tL ctlljC~fs UfD f r Dd u(i S r t poundlt~ t - f(~JtCVrLta (~J~ s cA1M7F fJj tkcyeq~J C~~

f c dvet s eJMtLj S i tu t1 ampt

Oetcll11Itt hOlV-ectLh rroducJ cv~cd r((7(~ftt-JI cJ~1ltlcfd lilI11bYvjV 1f)f7ed f_ C11~~~-e 7flL ((flo 4trc (~1QitS t~ (q~-cd (rYl l l~I(ltitJ ~Y~ fu 6a~ct J yt1( Ih~yenl

(0) ( v loJJ e~ util byI U yenl1 v~LlA us A1Ir +e tN ~ r~ e 1(U5oh1 pI II) 16( So ~ solve

Ke ~ [ HJ J~ _ CJ)()r~7) ) b [141 rrJ - (GSv-)OhIO-) [50 5]

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 2: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Equilibrium 2

B Solution Equilibrium (NOTE MUST BE SATURATED SOLUTIONS)

1 Gases in Liquids The rate of gas dissolving in a liquid =the rate of gas ~

escaping the liquid

2 Solids in Liquids the rate ofdissolving = the rate ofcrystallization S(rLrot-t~

ox) sed CO)(9) ~ (OJ(Q1) J t) tNeJu AIcitS) ~ N tashybull j t- I e- DI5solveJ

3 Chemical Equilibrium tlaquo2laquo ()1lt- u J1ltltgt I

A The point at which the concentrations of all reactants and products cease to

change with time

B The rate at which reactants are making products equals the rate at which

products are making reactants

C When reactants are first mixed only the forward reaction occurs Over time as

products are formed the rate ofthe forward reaction slows as reactants are

used up (concentration decreases) and the reverse reaction speeds up because

the concentration ofproducts increases This occurs until the rates of the two

reactions are equal ~iB~AB

Forward Reaction

~~

Time ~

5V1lh4 ~ At-B)

- j lt I lt J S )~n~ _J i - -( ie rt q ~~tlf4 v~d ()P

Reverse Reaction

Time

fyenJ-I~ no 48 I

rctif lMlto KS q lt + ( oj iJC ~ lt tOf Yh I

Equilibrium

Time

fiyW4 r d f rC liC ~)e (rltU) Pee Dyr4Z

euroraJ ~

Equilibrium 3

4 Law ofMass Action

A Founded by Maximilian Goldberg and Peter Waage in 1864

B Shows the relationship between the concentration of the reactants and the

concentration of the products for a reaction at equilibrium

C aka Equilibrium Expression 41 0 3 +6Noce ~ JA(J3 t 3NaO 1 Given the hypothetical equation aA + bB ~ cC + dD

a Lower case letters represent the coefficient ( ofmoles)

b Upper case letters represent the compound

2 Kc =K =[Ct[Dt Products over reactants ~ = fA 1J~l-fJJ()ffJJ3 ~ q [At[Bt [J)~~J [N~(JJo

a The square brackets indicate the equilibrium concentration

b The exponents are the coefficient$

c Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

3 Kc =Keq = equilibrium constant

a-tm ttnitamp vnfrs ampzt~4 (Yv 1It t(ul~

b independent ofstarting reactant concentrations

4 Interpreting the magnitude ofKeq I

a When Keq gt 1 the reaction is product favored PYC i cc wCr ltt~[()

th- r u(f 1fIb When Keq lt 1 the reaction is reactant favored

5 Calcolatmg Keq

A If all equilibrium concentrations are known simply plug numbers into the Keq

expression and solve

B Ifall concentrations are not known - use ICE box method

I = initial concentrations C =change in concentrations E =concentrations at equilibrium

1 The change in concentration of reactants is negative 2 The change in concentration of the products is positive

3 The change in concentration corresponds to the mole ratios (coeffs)

___

Narne A1Sllrlt-Y IavEQUILIBRIUM CONSTANT (K)

Write the expression for the equilibrium constant K for the reactions below

1 N2(g) + 3H 2(g) ~ 2NH3(g)

~Ke [ NIi ~ ] fJ MM-MPYmiddoto [iJJ ][H]3

2 2KCIOis) ~ 2KCI(s) + 30 (g)2

MMMtJdcft6 = f5aJtO)jJ [O]s P4f7(

~ SolidS d~~

3 H 0(I) ~ H+(aq) + OH-(aq)2

111I Jl

Ke = [WJf2j-r LH][OH]cc

~ ff~~ (tJUA

4 2CO(g) + 02(g) ~ 2C02(g)

n f--1

K~ -= [COJ ] -1t ~-

[COJ~ [0)J 1

5 Li2C0

3(S) ~ 2Li+(aq) + C03-2(aq)

I iCU J gt[cO~-J = [LJ lt] J [CO~-] f1 1-11keD 0 -[L~

501lds d~L~

bull

1_amp_ llII~LL 70 CCllndn Irtinnni Fnir Inc

4

__ ___

Name ________CALCULATIONS USING lIiE EQUILIBRIUM CONSTANT

Using the equilibrium constant expressions you determined on page 79 calculate the value of K when

~

1 [NH3J = 00100 M [N2] = 00200 M [H2] = 00200 M

kit - fOIJ~ ~ Prou ismiddot lfJY(J( [o~r[9JJ b~S tshy

2 [deg21 = 00500 M

Kt6 J~(OS] )C )lt 10 -I f~ ~itdalt-tgt ftr VdY(J CK~

B [H+) = 1 X 108 M [OH] = 1 X 106 M

K -= 010 R)DXlJtJ D-~ W ~

~

qa l ~lt (qIJortd

4 [CO] = 20 M [02] = 15 M [C02] = 30 M

kt~ - [ - J) _I

() r L - 5 ML-~J I ~J

iou c JrVdY(c

5 [Li+] = 02 M [C032] = 01 M

YIb shy [ ~] l[J -= (JO L1 M1 shy d~ tf ( 1tLl~ 1 ( f (

I 0( 1 _bullbull _Lt I _t~ I ~ _

c[ Eo) 11gt~e-fru

Equilibrium 4 aJ 71 ~i 01

-7C Practice 1

l

IS + shy

l

dhO shy

middot~d _

lrti~ shy~ shy

A mixture of 500xlO-3 mole ofH2 and 1000xlO-2 moles of12 is placed in a

5000L container at 448degC and allowed to come to equilibrium Analysis

of the equilibrium mixture shows that the concentration ofHI is 187xlOmiddot3 M

Calculate Keq at 448degC for the reaction ~li eyruwgt

I ~

J __ r~p( (gt lt -1 1v

U~ JIVey mfo +0 r-t Molan Ius tv sfart fJ III -fu tx)Xes

r-1 d ~ QJ25M ~ 001 N 51shy

1 0 (fI(P_ - DOd H ~- ~J 5L F-d CrJ tlJhaf yfJlA knew tcbozmiddotd )y711) vmiddot--tr( )) Vvt)( (

- 1tv --ll 0tL ctlljC~fs UfD f r Dd u(i S r t poundlt~ t - f(~JtCVrLta (~J~ s cA1M7F fJj tkcyeq~J C~~

f c dvet s eJMtLj S i tu t1 ampt

Oetcll11Itt hOlV-ectLh rroducJ cv~cd r((7(~ftt-JI cJ~1ltlcfd lilI11bYvjV 1f)f7ed f_ C11~~~-e 7flL ((flo 4trc (~1QitS t~ (q~-cd (rYl l l~I(ltitJ ~Y~ fu 6a~ct J yt1( Ih~yenl

(0) ( v loJJ e~ util byI U yenl1 v~LlA us A1Ir +e tN ~ r~ e 1(U5oh1 pI II) 16( So ~ solve

Ke ~ [ HJ J~ _ CJ)()r~7) ) b [141 rrJ - (GSv-)OhIO-) [50 5]

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 3: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Equilibrium 3

4 Law ofMass Action

A Founded by Maximilian Goldberg and Peter Waage in 1864

B Shows the relationship between the concentration of the reactants and the

concentration of the products for a reaction at equilibrium

C aka Equilibrium Expression 41 0 3 +6Noce ~ JA(J3 t 3NaO 1 Given the hypothetical equation aA + bB ~ cC + dD

a Lower case letters represent the coefficient ( ofmoles)

b Upper case letters represent the compound

2 Kc =K =[Ct[Dt Products over reactants ~ = fA 1J~l-fJJ()ffJJ3 ~ q [At[Bt [J)~~J [N~(JJo

a The square brackets indicate the equilibrium concentration

b The exponents are the coefficient$

c Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

3 Kc =Keq = equilibrium constant

a-tm ttnitamp vnfrs ampzt~4 (Yv 1It t(ul~

b independent ofstarting reactant concentrations

4 Interpreting the magnitude ofKeq I

a When Keq gt 1 the reaction is product favored PYC i cc wCr ltt~[()

th- r u(f 1fIb When Keq lt 1 the reaction is reactant favored

5 Calcolatmg Keq

A If all equilibrium concentrations are known simply plug numbers into the Keq

expression and solve

B Ifall concentrations are not known - use ICE box method

I = initial concentrations C =change in concentrations E =concentrations at equilibrium

1 The change in concentration of reactants is negative 2 The change in concentration of the products is positive

3 The change in concentration corresponds to the mole ratios (coeffs)

___

Narne A1Sllrlt-Y IavEQUILIBRIUM CONSTANT (K)

Write the expression for the equilibrium constant K for the reactions below

1 N2(g) + 3H 2(g) ~ 2NH3(g)

~Ke [ NIi ~ ] fJ MM-MPYmiddoto [iJJ ][H]3

2 2KCIOis) ~ 2KCI(s) + 30 (g)2

MMMtJdcft6 = f5aJtO)jJ [O]s P4f7(

~ SolidS d~~

3 H 0(I) ~ H+(aq) + OH-(aq)2

111I Jl

Ke = [WJf2j-r LH][OH]cc

~ ff~~ (tJUA

4 2CO(g) + 02(g) ~ 2C02(g)

n f--1

K~ -= [COJ ] -1t ~-

[COJ~ [0)J 1

5 Li2C0

3(S) ~ 2Li+(aq) + C03-2(aq)

I iCU J gt[cO~-J = [LJ lt] J [CO~-] f1 1-11keD 0 -[L~

501lds d~L~

bull

1_amp_ llII~LL 70 CCllndn Irtinnni Fnir Inc

4

__ ___

Name ________CALCULATIONS USING lIiE EQUILIBRIUM CONSTANT

Using the equilibrium constant expressions you determined on page 79 calculate the value of K when

~

1 [NH3J = 00100 M [N2] = 00200 M [H2] = 00200 M

kit - fOIJ~ ~ Prou ismiddot lfJY(J( [o~r[9JJ b~S tshy

2 [deg21 = 00500 M

Kt6 J~(OS] )C )lt 10 -I f~ ~itdalt-tgt ftr VdY(J CK~

B [H+) = 1 X 108 M [OH] = 1 X 106 M

K -= 010 R)DXlJtJ D-~ W ~

~

qa l ~lt (qIJortd

4 [CO] = 20 M [02] = 15 M [C02] = 30 M

kt~ - [ - J) _I

() r L - 5 ML-~J I ~J

iou c JrVdY(c

5 [Li+] = 02 M [C032] = 01 M

YIb shy [ ~] l[J -= (JO L1 M1 shy d~ tf ( 1tLl~ 1 ( f (

I 0( 1 _bullbull _Lt I _t~ I ~ _

c[ Eo) 11gt~e-fru

Equilibrium 4 aJ 71 ~i 01

-7C Practice 1

l

IS + shy

l

dhO shy

middot~d _

lrti~ shy~ shy

A mixture of 500xlO-3 mole ofH2 and 1000xlO-2 moles of12 is placed in a

5000L container at 448degC and allowed to come to equilibrium Analysis

of the equilibrium mixture shows that the concentration ofHI is 187xlOmiddot3 M

Calculate Keq at 448degC for the reaction ~li eyruwgt

I ~

J __ r~p( (gt lt -1 1v

U~ JIVey mfo +0 r-t Molan Ius tv sfart fJ III -fu tx)Xes

r-1 d ~ QJ25M ~ 001 N 51shy

1 0 (fI(P_ - DOd H ~- ~J 5L F-d CrJ tlJhaf yfJlA knew tcbozmiddotd )y711) vmiddot--tr( )) Vvt)( (

- 1tv --ll 0tL ctlljC~fs UfD f r Dd u(i S r t poundlt~ t - f(~JtCVrLta (~J~ s cA1M7F fJj tkcyeq~J C~~

f c dvet s eJMtLj S i tu t1 ampt

Oetcll11Itt hOlV-ectLh rroducJ cv~cd r((7(~ftt-JI cJ~1ltlcfd lilI11bYvjV 1f)f7ed f_ C11~~~-e 7flL ((flo 4trc (~1QitS t~ (q~-cd (rYl l l~I(ltitJ ~Y~ fu 6a~ct J yt1( Ih~yenl

(0) ( v loJJ e~ util byI U yenl1 v~LlA us A1Ir +e tN ~ r~ e 1(U5oh1 pI II) 16( So ~ solve

Ke ~ [ HJ J~ _ CJ)()r~7) ) b [141 rrJ - (GSv-)OhIO-) [50 5]

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 4: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

___

Narne A1Sllrlt-Y IavEQUILIBRIUM CONSTANT (K)

Write the expression for the equilibrium constant K for the reactions below

1 N2(g) + 3H 2(g) ~ 2NH3(g)

~Ke [ NIi ~ ] fJ MM-MPYmiddoto [iJJ ][H]3

2 2KCIOis) ~ 2KCI(s) + 30 (g)2

MMMtJdcft6 = f5aJtO)jJ [O]s P4f7(

~ SolidS d~~

3 H 0(I) ~ H+(aq) + OH-(aq)2

111I Jl

Ke = [WJf2j-r LH][OH]cc

~ ff~~ (tJUA

4 2CO(g) + 02(g) ~ 2C02(g)

n f--1

K~ -= [COJ ] -1t ~-

[COJ~ [0)J 1

5 Li2C0

3(S) ~ 2Li+(aq) + C03-2(aq)

I iCU J gt[cO~-J = [LJ lt] J [CO~-] f1 1-11keD 0 -[L~

501lds d~L~

bull

1_amp_ llII~LL 70 CCllndn Irtinnni Fnir Inc

4

__ ___

Name ________CALCULATIONS USING lIiE EQUILIBRIUM CONSTANT

Using the equilibrium constant expressions you determined on page 79 calculate the value of K when

~

1 [NH3J = 00100 M [N2] = 00200 M [H2] = 00200 M

kit - fOIJ~ ~ Prou ismiddot lfJY(J( [o~r[9JJ b~S tshy

2 [deg21 = 00500 M

Kt6 J~(OS] )C )lt 10 -I f~ ~itdalt-tgt ftr VdY(J CK~

B [H+) = 1 X 108 M [OH] = 1 X 106 M

K -= 010 R)DXlJtJ D-~ W ~

~

qa l ~lt (qIJortd

4 [CO] = 20 M [02] = 15 M [C02] = 30 M

kt~ - [ - J) _I

() r L - 5 ML-~J I ~J

iou c JrVdY(c

5 [Li+] = 02 M [C032] = 01 M

YIb shy [ ~] l[J -= (JO L1 M1 shy d~ tf ( 1tLl~ 1 ( f (

I 0( 1 _bullbull _Lt I _t~ I ~ _

c[ Eo) 11gt~e-fru

Equilibrium 4 aJ 71 ~i 01

-7C Practice 1

l

IS + shy

l

dhO shy

middot~d _

lrti~ shy~ shy

A mixture of 500xlO-3 mole ofH2 and 1000xlO-2 moles of12 is placed in a

5000L container at 448degC and allowed to come to equilibrium Analysis

of the equilibrium mixture shows that the concentration ofHI is 187xlOmiddot3 M

Calculate Keq at 448degC for the reaction ~li eyruwgt

I ~

J __ r~p( (gt lt -1 1v

U~ JIVey mfo +0 r-t Molan Ius tv sfart fJ III -fu tx)Xes

r-1 d ~ QJ25M ~ 001 N 51shy

1 0 (fI(P_ - DOd H ~- ~J 5L F-d CrJ tlJhaf yfJlA knew tcbozmiddotd )y711) vmiddot--tr( )) Vvt)( (

- 1tv --ll 0tL ctlljC~fs UfD f r Dd u(i S r t poundlt~ t - f(~JtCVrLta (~J~ s cA1M7F fJj tkcyeq~J C~~

f c dvet s eJMtLj S i tu t1 ampt

Oetcll11Itt hOlV-ectLh rroducJ cv~cd r((7(~ftt-JI cJ~1ltlcfd lilI11bYvjV 1f)f7ed f_ C11~~~-e 7flL ((flo 4trc (~1QitS t~ (q~-cd (rYl l l~I(ltitJ ~Y~ fu 6a~ct J yt1( Ih~yenl

(0) ( v loJJ e~ util byI U yenl1 v~LlA us A1Ir +e tN ~ r~ e 1(U5oh1 pI II) 16( So ~ solve

Ke ~ [ HJ J~ _ CJ)()r~7) ) b [141 rrJ - (GSv-)OhIO-) [50 5]

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 5: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

__ ___

Name ________CALCULATIONS USING lIiE EQUILIBRIUM CONSTANT

Using the equilibrium constant expressions you determined on page 79 calculate the value of K when

~

1 [NH3J = 00100 M [N2] = 00200 M [H2] = 00200 M

kit - fOIJ~ ~ Prou ismiddot lfJY(J( [o~r[9JJ b~S tshy

2 [deg21 = 00500 M

Kt6 J~(OS] )C )lt 10 -I f~ ~itdalt-tgt ftr VdY(J CK~

B [H+) = 1 X 108 M [OH] = 1 X 106 M

K -= 010 R)DXlJtJ D-~ W ~

~

qa l ~lt (qIJortd

4 [CO] = 20 M [02] = 15 M [C02] = 30 M

kt~ - [ - J) _I

() r L - 5 ML-~J I ~J

iou c JrVdY(c

5 [Li+] = 02 M [C032] = 01 M

YIb shy [ ~] l[J -= (JO L1 M1 shy d~ tf ( 1tLl~ 1 ( f (

I 0( 1 _bullbull _Lt I _t~ I ~ _

c[ Eo) 11gt~e-fru

Equilibrium 4 aJ 71 ~i 01

-7C Practice 1

l

IS + shy

l

dhO shy

middot~d _

lrti~ shy~ shy

A mixture of 500xlO-3 mole ofH2 and 1000xlO-2 moles of12 is placed in a

5000L container at 448degC and allowed to come to equilibrium Analysis

of the equilibrium mixture shows that the concentration ofHI is 187xlOmiddot3 M

Calculate Keq at 448degC for the reaction ~li eyruwgt

I ~

J __ r~p( (gt lt -1 1v

U~ JIVey mfo +0 r-t Molan Ius tv sfart fJ III -fu tx)Xes

r-1 d ~ QJ25M ~ 001 N 51shy

1 0 (fI(P_ - DOd H ~- ~J 5L F-d CrJ tlJhaf yfJlA knew tcbozmiddotd )y711) vmiddot--tr( )) Vvt)( (

- 1tv --ll 0tL ctlljC~fs UfD f r Dd u(i S r t poundlt~ t - f(~JtCVrLta (~J~ s cA1M7F fJj tkcyeq~J C~~

f c dvet s eJMtLj S i tu t1 ampt

Oetcll11Itt hOlV-ectLh rroducJ cv~cd r((7(~ftt-JI cJ~1ltlcfd lilI11bYvjV 1f)f7ed f_ C11~~~-e 7flL ((flo 4trc (~1QitS t~ (q~-cd (rYl l l~I(ltitJ ~Y~ fu 6a~ct J yt1( Ih~yenl

(0) ( v loJJ e~ util byI U yenl1 v~LlA us A1Ir +e tN ~ r~ e 1(U5oh1 pI II) 16( So ~ solve

Ke ~ [ HJ J~ _ CJ)()r~7) ) b [141 rrJ - (GSv-)OhIO-) [50 5]

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 6: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

c[ Eo) 11gt~e-fru

Equilibrium 4 aJ 71 ~i 01

-7C Practice 1

l

IS + shy

l

dhO shy

middot~d _

lrti~ shy~ shy

A mixture of 500xlO-3 mole ofH2 and 1000xlO-2 moles of12 is placed in a

5000L container at 448degC and allowed to come to equilibrium Analysis

of the equilibrium mixture shows that the concentration ofHI is 187xlOmiddot3 M

Calculate Keq at 448degC for the reaction ~li eyruwgt

I ~

J __ r~p( (gt lt -1 1v

U~ JIVey mfo +0 r-t Molan Ius tv sfart fJ III -fu tx)Xes

r-1 d ~ QJ25M ~ 001 N 51shy

1 0 (fI(P_ - DOd H ~- ~J 5L F-d CrJ tlJhaf yfJlA knew tcbozmiddotd )y711) vmiddot--tr( )) Vvt)( (

- 1tv --ll 0tL ctlljC~fs UfD f r Dd u(i S r t poundlt~ t - f(~JtCVrLta (~J~ s cA1M7F fJj tkcyeq~J C~~

f c dvet s eJMtLj S i tu t1 ampt

Oetcll11Itt hOlV-ectLh rroducJ cv~cd r((7(~ftt-JI cJ~1ltlcfd lilI11bYvjV 1f)f7ed f_ C11~~~-e 7flL ((flo 4trc (~1QitS t~ (q~-cd (rYl l l~I(ltitJ ~Y~ fu 6a~ct J yt1( Ih~yenl

(0) ( v loJJ e~ util byI U yenl1 v~LlA us A1Ir +e tN ~ r~ e 1(U5oh1 pI II) 16( So ~ solve

Ke ~ [ HJ J~ _ CJ)()r~7) ) b [141 rrJ - (GSv-)OhIO-) [50 5]

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 7: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Equilibrium 5

D Practice 2

Sulfur trioxide decomposes at high temperature in a sealed container ~

according to the following reaction 2803 (g) 2802 (g) + ~ (g)

Initially the vessel is charged at lOOOK with 803 (g) with a concentration of

11 1 609xlO-3 M At equilibrium the S03 (g) concentration is 244xlO-3 M r- ~ ~ 6t~iv1

Calculate the value ofKc at lOOOK

503(3) ~ ~5())(t) ~CdCs__--( IltI--~--oa-O~ 3M-~-- O-----~-~[ Jlc 0 M

bU1 ~ ~ x I __ 71 y) -i cA1rf1

C -gt3blt- 105 M+ibs~D-~~lsect~ID_ ~ ll ltD~ ~~ I J

~blt1-IJi)- t rJ-~q~IO-~ M 315 ~ 10 MIJS~IO fI- nt 1)

K( ~ [55-1)[01 _ C -2j(I6~tiQ~ [C n 1 ----- 1 f Yi IOS) ~

-JJ 0lt I

f---

7gt Kc ~ uO~ rl

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 8: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

I

~Q Yr~y_b( v~ IJ~ -~ ~ lYY ~ _ ~ _~ bull r~~~ A ~w P f~blampI1f2 ~dl ~_c- i~i~ _iL~ ll nilt ~ t ~l

I ~~ jiJ- I middot - _ ~ j S ~~I t 1 Hydrogen chloride reacts with oxygen to yield chlorine and water Equilibrium can be established with this reaction An experiment was performed in a closed vessel starting with a

- mixture of 050 MHel and 0050 M O2 The amount of chlorine was monitored until no change was observed at 0048 Mchlorine What is Keq for this reaction

~hre -f 0d ~JCl) + JJ- 0 ~l--lt---- ~ ~ -~-

f ~ 024

5 1 DS f V 0

--096-r--ID)~--J---~-Ul~- -I +-middotC~- kif [ofa)Lcq~Lgt oorz i_____-_H _ ~ ____ [ full) 1[ tjJCJ

_~o_~ J OUmiddot t Oi

~

I Og j

2 Using the following reaction H2 + h ~ 2 HI calculate all three equilibrium concentrations

when fHi~o ~ 0200M and ~ = 640 y- ~~~~J-~rIf+i ~ -~j -- t~~X - ~-x 1-1 JY

r ) __ _ __- Ke 61 CJx shyb J-x )(f 2~)

[lt~ I 10 ) - middot1b 01H

amp= J-x =) b - ilC =Ax CTa )Z = 16 =- 0411-

bull ~-)lt 6 It)lt [H1]ft = Jlh) ~ 311 I II =- X

3 Given this equation H2 + Br2~ 2 HBr calculate all three equilibrium concentrations when 0500 mole each of H2 and Br2 are mixed in a200 Lcontainer and Keq = 360

S -lC All

--- - rtl) Id shy [ Jf)1 =J ) famp7 -=- middot06)lt M Imiddot

- - ~

-laquof c---------middotmiddot-~l-middot-~middot--~ - - -~ - -1- l- ix [8f)J ~ middotV6dSM

~~----middot-1~-middotmiddotmiddot~middotmiddot~middot-~)lt- j A) J I J )ltf [HI$(J~ J(~7S) ~ 37S H

---gt--------- --~

l(cr J~) ~ =C b - h- ~gt I S -by ) ()) -AXJC-) 1) - y J lt 6 ~ J bull I~ 75 )(

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 9: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

I

Ishy4 Calculate the equilibrium constant Ieq at 25degC for the reaction 2NOCI(g) t 2NO(g) + Cl2(g)

using the following information In one experiment 200 mol of NOCI is placed in a 100L flask and the concentration of NO after equilibrium is achieved is 066 molL

c(NOLR ~ oNO i (Q ~

-_~~ ~~ Z~q ~

I j ~ ~~ -( )~

Ki1pound -= 33) 6h _ - DgO I () I~l

5 Amixture of 075 mol of N2 and 120 mol of H2 are placed in a 30 liter container When the reaction N2 (g) + 3H2 (g) + 2NH3 (g) reaches equilibrium [HJ = 0100 M What are the values of [N) and rNHsJ at equilibrium

IV 5- ~ Js N( f 3 H -it N H ~ ~ 1 _____ __ __~c ~_

~ middot1 0 HI ~ yen tM - -~ - ~ ~___~____I ff b - gt ( 7I

1f5middot 1 dshyi- ~---- ---- -~~ ~ ~ -~- _shy

~eN J~b - ~-M [IVH~j JM

6 Amixture of 25 moles H20 and 100 g of Care placed in a 50-L container and allowed to come to equilibrium subject to the following reaction C(s) + H20(g) ~ CO(g) + H2(g) The equilibrium concentration of H1]dIOgen is found to be fHJ = 0040 M What is the equilibrium concentration of water [H20]

HJo J5- - to S 1 C(~~ + 1)0(9) (0 (V 7 1--14- (ltj) SO

( l- - 17M So

~

-

_

--

ltgt ~~ shy - -~

7 05 0 -~-

-04 01

01 middotO~

-shy O r

I

~~ -~--J01 _--1

l

I O-i

[Hj)Je~ - 01 ~

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 10: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

I

I

~

Equilibrium 6

6 Reaction Quotient (Q)

A The result of substituting concentration values into the equilibrium expression l laquoB If Q equals Keq when the reaction is at equilibrium ~ C If Q is greater than Keq the reaction will move from right to left until equilibrium

is reacted

D If Q is less than Keq the reaction will move from left to right until equilibrium is

reached

E Practice

1 At 100degC the reaction COC12 (g) CO(g) + Cl2 (g) has an equilibrium constant

of 2 19x 1 0-10bull Are the follOwing mixtures at equilibrilPll If not indicate the

direction that the reaction will proceed to reach equilibrium [(DJ[Ci~J

A [COCI21= 500xlO-2 M~fO [COU)] J I I q X ((j 10[CO] = 331x10-6 M

[CI2] = 331xl0-6 M

l B [COCI2] = 350xlO-3M CJ ~ [CO]=111x10-5 M 03xO-i gt Keg bull

[CI2] =325xl0-6 M

C [COCI21= 145 M

t6D-1) lt k~ [CO] = 156xlO-6 M ~

[CI2] = 156xlO-6 M

2 At 448degC Keq = 51 for the reaction H2 (g) + 12 (g) 2HI(g)

Predict how the reaction will proceed if 20xlO-2 moles of HI 1Oxl0-2

moles

ofH2 and 30xlO-2 moles 12 are in a 20L container

HJ- ~ 01 f1 [HI] l 01) 33Q= shyH 21-- = 005 MJ J [f-td] [ I d1- (oosyoS)

l r) I~ Ol5M I

I bull

d- --Q L Keb --7

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 11: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Chemistry WORKSHEET - 16-6 Calculating Reaction Quotients [(~-~~~~~--~~~ ~~~~1~(-~~ Answer the following questions about equilibrium

1 At 740degC Keq = 00060 for the decomposition of calcium carbonate (CaC03) Find Qand predict how the reaction will proceed if [C02] = 0004M

Ca9J1(s) H CaO(s) + C02 (g) G=~ lty~ -

~ The equilibrium constant for the following reaction at 527degC is 510 If [CO] = 015 M [H20] = 025 M [H2] =

042 M and [C02l 037 M calculate Q and determine how the reaction will proceed (tf)~ IJ 111

1lt()5 1

CO (g) + H20 (g) H H2 (g) + CO2 (g) Qltkt ~- 3 At 340degC Keq = 0064 for the reaction of

rust with hydrogen gas Given the [H2] =

045 M and [H20] = 037 M fmd Qand predict how the reaction will proceed

F~s) + 3H2 (g) H 2Fe(s)+ 3H20 (g) Q)kllf p S0lt-- -Ie

4 The equilibrium constant for the following reaction at 2130degC is 00025 If [N2] = 081 M [02] = 075 M and [NO] = 0030 M fmd Qand determine the direction in which the reaction will proceed

N2 (g) + O2 (g) H 2NO (g)

DSl 005 -ii(7S)

Chemistry Q lt Ket ~

5 At 500degC the equilibrium constant for the following reaction is 0080 Given that [NH3] = 00596 M [N2] 0600 M and [H2] =Q420 M fmd Qand predict how the reaction will proceed ( 0 1y

N2 (g) + 3H2

(g) H 2NH3 (g) (of)) ~ 08

Q Ket

6 For the decomposition of antimony pentachloride (SbCls) Keq = 00251 What is the value of Q if [SbCls] = 0095 M [SbCh] = 0020 M and [Ch] = 0050 M How will this reaction proceed )

(I~H--- () 1 SbCls (g) H SbCh (g) + Ch (g) oefshy

Qltklt - 7 At loooec Keq = 10 X 10-13 for the

following reaction If [HF] =230 M [H2] =0540 M and [F2] = 038 M determine the value ofQ and predict

I ~~ (H)_ tJOIfhow the reaction will proceed 3 1

2HF (g) H H2 (g) + F2 (g)

Q gt Klb ~

8 At 1227 degC Keq for the following reaction is 015 If [S02] =0344 M [02] =0172 M and [S03] = 0056 M find Q and determine how the reaction will proceed

~ - 5 2802(g) + O2(g) H 2803(g) N 1J( 7))

Q--k

WSl6-6ReactionQuoffent

~

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 12: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Equilibrium 7 7 Solubility Product Constant (Ksp)

A For saturated solutions equilibrium is established between the ions

CJin solution and the excess solid

B The solubility constant expresses the degree to which a solute

dissolves in water

1 The lower the value of Ksp the lower the dissolved amount

2 The higher the value of Ksp the higher the dissolved amount

C Given the hypothetical equation AaBb (5) + aAq) + bB-(aq)

1 Lower case letters represent the number of moles

2 Upper case letters represent the compound

D Ksp - [A+][B_]b Products over reactants

1 The square brackets indicate the concentration (molarity M)

2 The exponents are the coefficients

3 Pure solids and liquids are not included in the equilibrium

expression because their concentrations are constant

E Interpreting the magnitude of Ksp

1 When the ion product lt Ksp NO PPT will form

2 When the ion product = Ksp NO PPTwill form

3 When the ion productgt Ksp PPT WILL form

u

u

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 13: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Odd t1)

Chemistry WORKSHEET - 16~9

C1~ jJ I7PifSolubili1y Equilibria ~~~~~~~~(~ ~~-~~~

Answer the following questions about equilibrium

19 Write the expression for the solubility v 10-7 M What is the value ofKsp for~ ( ~ product constant for MgCh[1J f Jflat AgBr 71) 710 - r~ 50)( 10 ~ I~

y 8 Write the solubility equilibrium for FeS04 [Ft~IJC50-J lILA sample of MgC03 (s) is added to pure

water and allowed to come to ~) Write the expression for the solubility equilibrium at 2SoC The concentration

product constant for Zn(OH)2 [zoJ[fOfd of Mg2+ is 63 x 10-3M at equilibrium rJ 4 Write the solubility equilibrium for if What is the value of Ksp for MgC03

CU(OH)2 LCqdegJ [OItJ~ ~)lt f6-s-JO 12At 2SoC the concentration of S~+ ions 1

j Write the expression for the solubility in a saturated solution of Sr(OH)2 is 431 product constant for Ah(S04)3 CAI1J[50tJ3 X 10-2M What is the value ofKsp for r) s p

~ sect Write the solubility equilibrium for Sr(OH)2 Kft-[5f J[oHli) l shy

Ca3(P04)2 [Cq ~rLp()1middotJgt _~ k5f ~[Ol~IJ[)iU4-f) 5dX10 I

I L 13What are the equilibrium concentrations 7 A sample of srCo3(s) is added to pure v of the dissolved ions in a saturated

~ water and allowed to come to[5r~ =(chj solution ofFe(OH)2 at 2SoC (Ksp = 18L Ce~~at2S~C The co~~en~tion x 10-15

) K~f [r(] [OHJI jlaquo())~_~ 15~ I~--o +ls40x 105 MateqUlhbnum 7 blxl[) - t)~ ~ I

What is the value ofKsp for srCo3 14What are the equi1ibrf~~Srtcenfi~fi~nS (A It -

ky =[5rJ[((3 j (r)-slld()S) of the dissolved ions in a saturated

_ 8 At 18degCt~e conce~tration of Pb2+ ions solution of~g2S0~a~~oC (Ksp ~ 1~ x f(~ rM

in a~jeasolut1on of lead oxalate 10-5) ~ i li a f L (PbC20 4) is S23 x 10-6 M What is the Od-~ ~ f ~~ ~ ~~ gtKltp

value ofKsp forbC204 (~lSWhat are the equilibrium concentrations k~f[rJPJjO~3 LS) 3)(JO[C)40 -j ) JI~O I ofPb2+andS2- in a saturated solutionof atJ 1

( ~~) A sample ofCu3P04 (s) is added to pure v PbS at 25degC (Ksp = 70 x Io-2~6 A

-1 -- water and allowed to come to 15 1 Itgt -I~ 11 (oJ

equilibrium at 2SoC The concentration 16What are the equilibrium concentrations I Lf i Ib of Cu + is 1OS x 10-5M at equilibrium of Ag + and S~ in a saturated solution What is the value of Ksp for CU3P04 of silver thiocyanate (AgSCN) at 2S0C

~7P -= [ev 1~[vo -1 [middotos b -~] ~[I oS ltIlrl- ] Lf 050-71 (Ksp = 116 x 10-12) 1gt 10 -

IOAt 2SoC the concentration of Ag+ ionS~) ~ ina saturated solution of AgBr is 707 x Yb SX I()- - I l t f~1 1k

WSl6-9SoubilityEquilibriaChemistry

J ltshyl J J )r5~ I ) xl)-S _ Ix] J (x ) (7

14)( gt bull 01)7 r ( lt )

bull u(

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 14: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

8 Le Chateliers Principle - When a stress is applied to a system the reaction will try to shift in a direction that

will relieve the stress 1hli1k db ftJlJJlivm Ilk~ a ftmiddotvd Set5~

Ex 02(g) + 2H2(g) ~ 2H20(l) + 572 kJ ZI

A Temperature

l T -= 1ltid eILYjY t T J AlJ ~jf

vy) l -r sfrecne5~rI8h+ ~ rettchiJ sh+1-S ~ to Otler(lYJrl bull ( Irllu--p tLJ ~) -Hv sfr~S

B ConcentratIon

When the concentration ofa reactant or a product is changed the system will shift in order to restore the original concentration as closely as possible

-Increasing the concentration of one substance causes the reaction to shift in the opposite direction -Decreasing the concentration of one substance causes the reaction to shift in the direction where the concentration decreased

-1-) ~ [O~] lty-t S5( S Ctp ~ r-tl1ch()h 5)fIs --gt J [101 )fye~~ njh+ ~ rt~chOgt1 si1Hs ~

C Pressure - Affects gases only -Increasing pressure pushes molecules closer together - increases concentration

-) l P ~+re$) S ltplck 6tC4 iI~ fr()f1l YIbie s amp6 )ct s L ~

-Ifboth sides of the reaction contain gases the side with more moles will be affected more ~~rt ~f1~

Ex) 2803 (g) ~ 2S~ (g) +02 (g)

J P Str-esze 5 n~hf ~ r ---7

- 1+ ~t 5 ~ ervtJ 4) flit s tr qc 5 (h 60 fll ilks 4 daArtF- ~ fre95VrL 1lt nt1 Jf $frts~ J

D Catalyst - Increases the forward and reverse rates equally so there will be no shift in the system

Heres a biological example ofan application ofLe Chateliers principle

Hemoglobin (Hb) reacts with oxygen to form Hb02 a substance that transfers oxygen to the tissues in the body Carbon monoxide (CO) also reacts with Hb02 by the process below

tC1LU Jto lite ~

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 15: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

-----------------

Le Chateliers Principle Demonstration

Name An5Wf) kt V Date

CoCh 6H20 (aq) + 4cr (aq) + 50 kJ ~ CoCh (aq) + 6H20 (1)

(pink) (blue)-- Predictions

1 IfHCI is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

~Blu~

2 If water is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

fink ~

3 If heat is added to the system what prediction do you make for the color of the solution Explain your prediction using Le Chateliers principle

Blue ---7

~

4 If this system is put into ice-water and cooled what prediction do you make for the color of the system Explain your prediction using Le Chateliers principle

Pll1k ltshy

Actual Results

1 What color is the solution at room temperature

2 What color is the solution when HCI is added Compare it to the room temperature solution

3 What color is the solution placed in hot water Compare it to the mom temperature solution

l 4 What color is the solution placed in ice-water Compare it to the room temperature solution

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 16: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

L 1 Given the solution at equilibrium

Pbl2(s) f-jgt Pb2+(aq) + 2naq)

The addition of which nitrate salt will cause a decrease in the concentration of naq) (1) Pb(NO2 (3) LiNOs (2) Ca(NOS)2 (4) KNOs

_1_2 Given the reversible reaction

A(g) + B(g) f-jgt Cg) at equilibrium

If the concentration of A is increased at constant temperature and pressure which will also increase

(1) the rate of the forward reaction (2) the value of the equilibrium constant (3) the activation energy (4) the concentration of B

) 3 Given the equation representing a reaction at eqUilibrium

H2(g) + 12(g) + heat f-jgt 2HI(g)

Which change favors the reverse reaction (1) decreasing the concentration of HI(g) (2) decreasing the temperature (3) increasing the concentration of 12(g)

d(4) increasing the pressure

__4 Given the reaction at equilibrium

2 A(g) + 3 B(g) f-jgt A2Bs(g) + heat

Which change will not affect the equilibrium concentrations of A(g) B(g) and A2Bs(g)

(1) adding more A(g) (2) adding a catalyst (3) increasing the temperature (4) increasing the pressure

5 Given the reaction at eqUilibrium

4 HCI(g) + 02(g) f-jgt 2 CI2(g) + 2 H20(g)

If the pressure on the system is increased the concentration of CI2(g) will (1) decrease (3) remain the same (2) increase

LaAmmonia is produced commercially by the Haber reaction

N2(g) + 3 H2(g) f-jgt 2 NHs(g) + heat

The formation of ammonia is favored by

(1) an increase in pressure (2) a decrease in pressure (3) removal of N2(g) (4) removal of H2(g)

~7 Given the system at equilibrium

2POCla(g) + energy 2PC1ig) + 02(g)

Which changes occur when 02(g) is added to this system (1) The equilibrium shifts to the right and the

concentration of PCls(g) increases (2) The equilibrium shifts to the right and the

concentration of PCls(g) decreases (3) The eqUilibrium shifts to the left and the

concentration of PCls(g) increases (4) The equilibrium shifts to the left and the

concentration of PCI3(g) decreases

~8Given the reaction at equilibrium

N2(g) + 02(g) + energy f-jgt 2 NO(g) 1 Which change will result in a decrease in the amount of NO(g) formed (1) decreasing the pressure (2) decreasing the concentration of N2(g) (3) increasing the concentration of 02(g) (4) increasing the temperature

I 9 Given the system at equilibrium

N20 4(g) + 581 kJ f-jgt 2 N02g)

What will be the result of an increase in temperature at constant pressure (1) The equilibrium will shift to the left and the

concentration of N02(g) will decrease (2) The equilibrium will shift to the left and the

concentration of N02g) will increase (3) The eqUilibrium will shift to the right and the

concentration of N02(g) will decrease (4) The eqUilibrium will shift to the right and the

concentration of N02(g) will increase

~

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 17: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

Le Chateliers Principle

0~ame ____________ Date ---- shy

- When a stress is applied to a system at equilibrium the reaction will try to shift in a direction that will relieve the stress

Ex) N2 (9) + 3H2 (9) ~ 2NH3 (9) + Heat

Stress

la) t Concentration of reactants

Ib) t Concentration of products

2a) 1Concentration of reactants

2b) 1Concentration of~ products

3a) t Temperature of system

3b) 1 Temperature of system

4a) t Pressure of system

4b) 1 Pressure of system

5) Add a catalyst

Shift in Equilibrium

~---

~

---7 ~

~- ~

~--- -I

Effect

tp~

t (tlJc

l t~~~+

l (cd

t Itoct J

t fr()J I

t froJ I

l ((eurotd

fQst~ F~ re I

L

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~

Page 18: Equilibrium 1 Eqllllbl.. - WikispacesPacket... · Eqllllb"l.. Equilibrium 1 ~ Equilibrium: the forward and reverse reactions occur at the same rate (represented by a double arrow

LeChatelier Practice

I Consider the following equilibrium system in a closed container

Ni(s) + 4 CO(g) ~ Ni(CO)4(g) t1H -161k1 ~

In which direction will the equilibrium shift in response to each change and what will be the effect on the indicated quantity

(a)

(b)

(c)

Change

add Ni(s)

raise temperature

add CO(g)

Direction of Shift

( -- -t- or no chanie)

-gt ~

~

Effect on Quantity

[Ni(CO)4(g)]

[CO(g)]

[ Ni(s)]

Effect (increase decrease

or no change)

l l -lshy

(d)

(e)

(f)

(g)

remove Ni(CO)4(g)

decrease in pressure

lower temperature

remove CO(g)

~

ltE-shy

~ ~ -

[CO(g)]

[Ni(CO )4(g)]

[CO(g)]

[Ni(CO)4(g)]

t

t J

f ~ 2 The manufacture ofethanol is done as follows

CH2=CH2(g) + H20(g)~ CH3CH20H(g) + 46 k1 ~ (ethene) (ethanol)

a To get the maximum percentage conversion of the ethene into ethanol is a high orregemperature best Explain why

7

b Conversion ofethene into ethanol is favored by high pressures Explain why

----3J

MD(( 1~S JGS fh fef

c Vould adding extra steam favor the creation ofe or less ethanol Vhy

~ ~