KEiSolutions- Chapter 12 & 13

Academic ChemistryObjectives:• Describe the unique role of water in chemical and biologica-l-systems

• Develop and use general rules regarding solubility through investigations with aqueous solutions• Calculate the concentration of solutions in units of molarity

• Use molarity to calculate the dilutions of solutions

• Distinguish between types of solutions such as electrolytes and nonelectrolytes and unsaturated,

saturated, and supersaturated solutions

• Investigate factors that influence solubility such as temperature, through an essential lab

Vocabulary:1. Solution 6. Tyndall effect 11. Immiscible 16. Supersaturated2. Solute 7. Soluble 12. Solvation 17. Dilute3. Solvent 8. Insoluble 13.Solubility 18. Concentrated4. Colloid 9. Precipitate 14. Unsaturated5. Suspension 10. Miscible 15. Saturated

Provided:• Henry s Law: Si - S2

Pi P2

• % by mass = mass solute x 100mass solution

• Molarity (M) = mol Mi Vi = M2 V2L

• Periodic Table, Polyatomic Ions List, Solubility Rules, Solubility Graphs, Calculator

CHECKLIST: How to be successful in OTHS Academic Chemistr Q Pay attention and take notes in class

Ask questions in class on material that is not clearWork every page in the practice packet for the unitCheck answers to the practice packet online at http://othsacademicchemistrv.weeblv.com/

Come to tutorials with any chemistry teacher

Do the online homework and check solutions once they become availableQ Always do the practice test for every test & ask good questions on review day

Keep up with the calendar for the class/be aware of approaching quizzes, tests, & other deadlinesUse videos posted on website as a quick and convenient tutorial

Read the chapter in the book

P l P 2 Pg3 Pg4 Pg5 Pg6 Pg7 Pg8 Pg9

Name Period

Solutions Vocabulary Cross-Word Puzzle

Aei05S - solutio J. k bwiogeawoBs smcinsr* with wexf Mali ps &ieles Ishafe do bo£ sefcfele wife of t3se aolafeiws eoepiHed of a aelafee aad a sal enfe

5,. & sel feieis tiafe eoiifeaias feix aaatam aae fe of solH&e fox a given amBsa&i of solvest: afe a par&iEitl x tJspex fKte SATlieATBb

7. 2s ,insoluble solid aafewdal tisal; is psniiKeii is. do fale replacessent; seafitaaos ?/?eo pitate

1§. k sistEiire wish sadim siaed paxsiid.es Sh S do noS seSfele s s COLLO J)

II. Tfae issolving xse iai is a solusiBE solve/ r

UL 'does nos issolve N OLO Q e¬

ls,. btSsBBogpstmu aiixS xe vitih l rge p xSieles that, settle oat S(J PEfi/SI ON

14. Describes sol Sioas fehafe eontains a relasively snail .aaiota of solirre £)l U TB s . _

15. ie proc ss that scrass »he». n ionic olid dissolv s; the ions ax pull d rt and sExxomrie by otoeEt sslecules

Stans

I. Describes liq ids th dissolve i . ach other fA i S (El 3 EES-. Describes solsSisra th t cont iss xela iv lj large anosafe of olute Q N C SJ PR- fi TG

4. solution tha con in less solut than s tax ted soIsfeioE t a p rSiealar fees pesafiane MS TUEATt I)¦5 . olution, t cont ins sn» solute t an it can eoxe c ilf old at p r icul r twqpwatnse; BStatoeSU/ti* Sdfl -/ TtrjE

6. Effect c u d bj sc ttering of lig t y articles in a colloid or sa pens n® t YA/ &AL-E B't~1hlzC T~

-0 .. Describes liqui s ha do not dissolve in each other JWt lS t 6LE

5. "dissol es" SOLU 6L(EII. he airi.TOai aaowffi of sol te th t dis olves i . giv s amoiHis ©f solvent a rfeiculax feesjerafease sotMdiu I v

15 . The dissolved p rticles in. a sol ticai lute

i

Practice Solubility Behavior1. For each action, write whether it would increase (I), decrease (D), or have no effect (N), on the solubility of

the solid solute. 5o L of/3i t t y Hcn*J MUCH wiLL D/SSoLVEfo£ Soi il '

a. Decreasing the temperature of the solution

b. Decreasing the pressure over the solution N

TtMPefLp TUte t SOLUBiUT

Pfc£SS><J e A/D CFe J otJ v5<?F/-£

2. For each action, write whether it would increase (I), decrease (D), or have no effect (N), on the solubility ofthe gaseous solute. Ho W UCH WILL Di So LVE

PC G.rt££S-a. Placing a soda in the refrigerator

b. Increasing the temperature of the solution _

W e 7£ P€P u££ SPL SlL/7

c. Decreasing the pressure around the solution ze $O j£tU i '

3. For each action, write whether it would increase (I), decrease (D), or have no effect (N), on the RATE ofsolubility of the solute. o £VLU6lCiiy PAST £>fSso /E

(qraoda. Using a packet of sugar instead of a sugar cube

b. Heating up a sugar and tea solution

c. Stirring a solid solute into a solution of water

4. Pressure only affects the solubility of _ Qas es

HENRY S LAW S, _ g>2-_

? The solubility of O2 gas in water is 2.54 g/L at 1.79 atm pressure. What is the solubility if the pressureis decreased to 0.856 atm? 1 „ „

S, =

P,S,= 2-54 |L

P, = I- - vk

Si - 7V - m

S2 - (V5l 1 (0 156 *™)in a+m

1 2! j|u

I1 I' '

2. The solubility of N2 gas in water is 0.35 g/L at 2.5 atm pressure. What is the pressure if thesolubility increases to 0.48 g/L?

S, 0-35 |L

p»-- 2-5

- 0- 1 jlL

7

'I -

P,

F2 Pi -- (f0 jll-) 2 5afa )

\ 0 • SS j /l

3*4

2

SOLUBILITY CURVESAnswer the following questions basedon the solubility curve below.

Name

1. Which salt is least soluble in water 150

at 20° C? £ i4n

. , 1302. How many grams of potassium

12ochloride can be dissolved in 200 g o

<M 1 10of water at 80° C? ' ,0a !,

>//

-

0x2 =W# 1 uu

100 in g 90 .O *it3, At 40 C, how uch potassium 5

O 70V f Dj nitrate can be dissolved in 300 g of «»

3 if 100 3 *5 60wnt r?

/21-A

4. Which sa

I . . ,sr 1 65 in 3a>iWate/g 50NaC

K \

shows the least change 40

in solubility from 0° - 100° C?

f\ x C\ 1 Hrt HeS cu e 10

5. At 30° C, 90 g of sodium nitrate is 020 30 40 50 60 70 80 90 100

blNt- dissolved in 100 got ater. Is this Temperature (0°C)

solution saturated, unsaturated or

supersaturated?

Plcrh e- poinh: 30°C I l w Cu ye p/e NoJ O

6. A saturated solution of potassium chlorate is formed from one hundred grams of

(cCl 0 water. If the saturated solution is cooled from 80° C to 50° C, how many grams of

recipit te ore formed j

7. What compound shows a decrease in solubility from 0° to 100° C? / f <X

8. Which salt is most soluble at 10° C? -

9. Which salt Is least soluble at 50° C? _ i ao,

10. Which salt is least soluble at 90° C? Ain 61 f Not- Nth btcause. N 3 is> o. lp

Chemistry IF8766 ©instructional Fair, Inc.

Solubility Curves Worksheet #2Use the solubility curves below to answer the questions

150

140

130

120

1. Which substance is probably a gas? Why?

B cause CiL&ve, shows.decr is m solubJ't as o

100

90

2. Which substance has the highest solubilityat 20°C?

kr

3. Which substance is least soluble at 40°C?

KCID34. The solubility of which salt is least affected

by temperature?

N c\

MqC | 5. At 70°C, how much ammonium chloride canbe dissolved in 100 g water?

OXcn

8m

O

Ek=.

80

70

60

50

40

30

2010

7

-j

I

jCi=

><

y 10 20 30 0 50 60 70 80 90 100

Temperature {°C)6, At 70°C. how much ammonium chloride can be dissolved in 500 g water? , /

fca*5.= \ToO Mut\}o (j>0$yL 5) ssc <n

f H 7. At 90°C, how much ammonia can be dissolved in 200 g water? IOJ d t'SSo ses in (OO /0 X2 |2-O Nirt i 2 00

8. At 80°C, 40 g of potassium chloride is dissolved in 100 g water. Is the solution unsaturatecf i

kCI suPersaturated? unsa u pC

Ua fe/z)saturated, or

heJouj cuAve.

9. At 30°C, 13 g of potassium chlorate (KCIO3) is dissolved in 100 g water. Is the solution unsaturated,saturated, or supersaturated?

S fieAS d'uAa- fecI poio iS a bp A CuAi/e.

10. At 20°C, 145 g of potassium iodide is dissolved in 100 g water. Is the solution unsaturated, saturated, orsupersaturated?

Soc{\jL( Cit-co ~> poinJ /S on bh& CksawS-

11. A saturated solution of ammonium chloride is made with 100 g water at 90°C . How much ammoniumN qCI chloride would crystallize out if the solution is cooled to 50°C?

oib °\0oC

at 50eC 5c>j J l JlOcj j'2-Qq bJHif Cl

4

Solution Concentration Worksheet #1

Solutions are composed of a solute (what gets dissolved) and a solvent (what does the dissolving). In chemistrywe need to be able to express quantitatively exactly how much solute is dissolved in a given amount of solution.This quantitative description is known as the solution s concentration. You will learn two units for expressingsolution concentration.

impoft f~£Xv\ i~I. Percent by Mass % by mass mass solute x 100

mass solution* ( solution = solute + solvent )Sample Problems: 1. What is the % by mass of NaHCOs in a solution containing 20.0 g NaHCOs (solute) dissolved in 600.mL water (solvent)? The density of ater is 1.0 g/mL (so 1.0 g = 1.0 mL).

Mass of water = 600 g, % by mass = 20.0 g x 100 = 3.23 %(20.0 g + 600.g)

2. You have 1500.0 g of an aqueous bleach (NaCIO) solution. The percent by mass of the solute (NaCIO)is 3.62%. How many grams of NaCIO are in the solution?

Do a proportion: 3.62 = x100 1500 x = 54.3 NaCIO (solute)

3. Refer to #2. How many grams of solvent (water in this case, because it is an aqueous solution) are

present in this solution? How many mL is this?

You know the total mass of solution is 1500.0 g. 1500.0 g = solute + solvent1500.0 g = 54.3 g + x

No : I m i- waJr- fc ~ I a-PegI m t che/g j

Practice Problems:

x = 1445.7 g water (solvent)= 1445.7 mL water

(the density of water is 1 g/mL)

1. What is the % by mass of a sucrose solution containing 50.0 g sucrose in 500. mL water? .=: SDQg

mass of Sol te- 0-O mas Solu b'pn - 5fr. 5Qg

2. What is the % by mass of an iodine solution containing 2.0 g iodine

mass of Solute I-03br\as of ScLu c ~ 200.3 + 2.0 201,3

ojo Lf mass - . loo j 1-01%J 550- 3 1

(solute) in 200. g alcohol (solvent)?

o/aloH »mSS- x»0O °/0 \J 2J02-3

3. How many grams of KC1 are present in 1000. g of an a ueous solution that is 20.0% KC1 by mass?

•2-o Q = y

loo t ooo.4. Refer to #3. How many grams of solvent (water) are present in this solution?

SoLt-b'On = IOOO-3 mass Sote J- ( /a- 'Cr) - I OO -3- 200-J

m solute - Zo - I &OO3 j5. What is the mass of a solution that contains 25.0 g fructose and is 10.0% fructose by mass? ~

10-03 _

lOO

KEY:1. 9.09%2. 0.99%

I = (25 oS)fux>) =ris ' IOO3

3. 200. g

4. 800. g

5. 250.

esr\ bee i mole - ) J

Lu e/?G-

mol/L is abbreviated M

rX /£rnola e ma sII. Molarity Molarity = moles sol te

Liters solutionSample Problems:1. What is the molarity of a solution containing 0.50 mol lucose in 2.0 L solution?

Molarity = 0.50 mol = 0.25 mol/L = 0.25 M glucose2.0 L

2. What is the molarity of a solution containing 40.0 g NaCl in 700. mL of solution?

First change grams of solute to moles using molar ass: 40.0 g NaCl = 0.684 mol NaCl

Also change mL of solution to L| 700. mL = 0.700 L

Molarity = 0.684 mol = 0.977 M0.700 L

o/ CofVi/ej?3i0/ S

Yo In i e - ? USe L. in ih,s 'fb rxu.lc

3. How many ole of KI are dissolved in 3.00 L of a 0.125 M solution? How many grams of KI?

M = mol/L -> mol = M x L mol = (0.125 M) x (3.00 L) = 0.375 mol KI

Then change moles to grams usin molar mass: 0.375 mol KI = 62.3 g KI

Practice Problems:Calculate the molarity of each of the following:

6. 0.50 mol of HC1 in 1.0 L of solutionU. U.JU JUUUl Ul i I _l 111 l.U J 111 auituiuii \

Mc Li - mol 0-3O o> - (o SoJ L- I D l ~

7. 2.8 mol of HNO3 in 4.0 L of solution

Molae k, J sL Jjtrnol [pTlO Ajj/ L. h-nU O L.

8. 0.700 mol of NH4CI in 50.0 mL of solution . ~A

50-OmL 0-05OOL J aL = JL3°Z!2 . =I o O bOf

9. 25.0 g of NaCl in 250.00 mL of solutionL -0 Z5OOOLjrtolAA&j- ~25TCM Had* mol Na - NaCl 25D-0t? r t_ 7>2&OOOi

S% i-U+3 M CI I 1 11.-fill J10. 10.0 g of Cr(N03)3 in 325 mL of solution -

J Z39-00»lCr£M?3)3 J 1 ' !~C1Find the number of moles AND the number of grams of solute required for each of the following: IQ. /2- d j

1 n. 1.00 l of3.00 MNH4CI R r:i u 53 itfzjMhcl -./ Z nmol M l_ p ol - (Z'oo *)(

12. 500.0 mL of 0.250 MNaF

OOOmL- O-SCOOL j mol -(0- Z&Qrt) (0 ¦ ool-) =jO'/ Z5mo\ Na -[5-2Sc\ aff

13. 2.75 L of 3.0 M NaOH1J. ,. j tJl J.U 1VL INa ll r

fmol fa>.Oh4}f Z-l L) - / % 3 ol =.I 7 1 mol Nouoti

KEY:6. 0.50 M

7. 0.70 M8. 14.0 M

9. 1.71 M

1 mol NaoH

10. 0.129 M11. 3.00 mol, 161 g12. 0,125 mol, 5.25 g

13. 8.3 mol, 330 g

6

Practice Worksheet #2: Solution Concentration Units

Helpful formulas:

Mass % = mass solute x100mass solution

Molarity (M) = moles soluteL solution

1. You have 350 g of an aqueous bleach solution. The percent by mass of the solute(NaCIO) is 2.5 %. How many grams of NaCIO are in the solution?

-5- - X__

tooX = 2- - 75 NaCIO I

2. What is the % by mass of CeH Oe (glucose) in a solution containing 20.0 g glucosedissolved in 180 g water? SoUcrh n - O -Oj +/$Oj

\o mass - 20 03 x loo ~ I To• % JZOO

3. (a) What is the molarity of a solution containing 1.5 mol NaF in a 1.5 L solution?

Molaci r mol ±J> h M Na~F !L 1:5 L

(b) What is the molarity of a solution containing 50.0 g NaF in a 800 ml_ solution?

50 / mol aJ2 = ft me Na F 0i u - mzL NaF

dOOmL- ~ 0- L.

L~

-

0-8 0

[irt f c f[ 7j

4. How many grams of NaN03 are dissolved in 2.0 L of a 0.50 M solution?

mol M V L~

= (o SD*Yz o ) = LO . l Os, Is imoj ccMOi

5. What is the total solution volume if the concentration is 2.0 M and the amount ofdissolved KCI is 25.0 g?

2S 0<\ led 1 &L = 0- 5 mol ledJ 7a 55Ij ICCj

molc , M- molL.

L - o IM

1/o mt ( L-) = - 0 335 2*1 - 0-I 75LM Z o