Drill:•Determine the KQ/HQ ratio to make a buffer solution with a pH of 4.70

•Ka for HQ = 3.0 x 10-5

Drill: Calculate [H2Q], [HQ-], [Q-2], [H+], & pH of 0.20 M KHQ.

Ka1 = 2.0 x 10-4

Ka2 = 8.0 x 10-9

Solubility

Solubility•The amount of one substance that will dissolve in another

Precipitation• When dissolved

particles join together forming a new phase and exit the solution

Precipitate (ppt)•The new phase that

forms and leaves the solution

Ppt Examples•Water vapor combining

to form rain

• Dissolved ions combining to form a solid

Saturated Solution•When the maximum

amount of one substance is dissolved

in another

Precipitation•When more than the maximum amount of solute is added to a solution, a ppt will

form

Write the equilibrium expression for

AgCl(s) Ag+ + Cl-

Solubility Product

MX(s)

M+(aq) + X-

(aq)

Ksp =[M+][X-]

Solubility Product

MX2(s)

M+2(aq) + 2 X-

(aq)

Ksp =[M+2][X-]2

Drill: Write the equilibrium

expression for:

Al2(SO4)3

Drill:Write the reaction &

equilibrium expression when solid Fe2(SO4)3 is

added to water.

Solubility Calculations

•Calculate the solubility of

BaSO4(s)

•Ksp = 1.2 x 10-10

Solubility Product

BaSO4(s)

Ba+2(aq) + SO4

-2(aq)

Ksp =[Ba+2][SO4-2]

•Calculate the solubility of

SrCr2O7(s)

•Ksp = 2.5 x 10-13

•Calculate the solubility of

PbI2(s)

•Ksp = 8.0 x 10-9

•Calculate the solubility of

Mn2S3(s)

•Ksp = 1 x 10-98

Drill: Calculate the solubility of M3X4

Ksp for M3X4

= 6.9 x 10-207

Solubility Concepts

AgI(s) Ag+ + I-

Ksp = [Ag+][I-] at Eq.

Qsp = [Ag+][I-] init.

Solubility Concepts• If Qsp > Ksp a

precipitate will form

• If Qsp < Ksp no precipitate will form

150 mL 0.010 M KI is added to 100 mL 0.010

M Pb(NO3)2. Ksp for PbI2 = 8.0 x 10-9

•Will a ppt form?

AP CHM HW•Read: Chapter 16

•Problem: 13

•Page: 463

CHM II HW•Read: Chapter 20

•Problem: 17

•Page: 843

Drill:•10.0 mL 0.050 M KCl is added to 15 mL 0.075 M Pb(NO3)2. Ksp = 1.7 x 10-5

•Will a ppt form?

Drill: Calculate the solubility of AgI(s)

•Ksp = 1.5 x 10-16

Common Ion Solubility

Calculations

•Calculate the solubility of AgI(s)

in 0.10 M NaI

•Ksp = 1.5 x 10-16

Common Ion Effect

•Solubility of a solid is reduced when one of its ions is already

in solution

•Calculate the solubility of MZ2(s)

in

0.20 M M(NO3)2

Ksp = 2.0 x 10-15

•Calculate the solubility of M2Z3(s)

in

0.20 M M(NO3)3

Ksp = 2.0 x 10-16

AP CHM HW•Read: Chapter 16

•Problems: 18

•Page: 463

CHM II HW•Read: Chapter 20

•Problems: 19

•Page: 844

Drill: Calculate the solubility of CaCO3 in water. Ksp = 4.9 x 10-15

•Calculate the solubility of PbI2(s)

in 0.010 M NaI

•Ksp = 3.2 x 10-8

Aqueous NaI is added (dropwise) to a solution of 0.10 M AgNO3(s) &

0.10 M CuNO3

AgI Ksp = 1.0 x 10-16

CuI Ksp = 5.1 x 10-12

•Aqueous KCl is added (dropwise) to a solution

of 0.10 M AgNO3 & 0.10 M Cu(NO3)2

• AgCl Ksp = 1.8 x 10-10

•CuCl2 Ksp = 5.1 x 10-12

Test on Thursday or Friday

Drill: Calculate the solubility of

PbS(s)

Ksp = 1.0 x 10-28

Review

•Calculate the solubility of

PbCl2(s)

•Ksp = 1.6 x 10-5

•Calculate the solubility of Sc(OH)3(s)

•Ksp = 2.7 x 10-31

•Calculate the pH of Ca(OH)2 in

solution.

•Ksp = 4.0 x 10-6

Calculate the pH of LiCO3 in soln

Ksp = 8.2 x 10-4

Ka1 = 4.4 x 10-7

Ka2 = 4.7 x 10-11

•Calculate the solubility of AgI(s)

in 0.20 M NaI

•Ksp = 1.5 x 10-16

The solubility of MX2(s) is

2.0 x 10-5 M.

Calculate its Ksp

•Aqueous MgCl2 is added (dropwise) to a solution

of 0.10 M KOH & 0.10 M K2SO4

• Mg(OH)2 Ksp = 6.0 x 10-6

• MgSO4 Ksp = 5.6 x 10-5

Drill:•The solubility of YF3 is 2.0 x 10-8. Calculate the value of Ksp.