SolubilityLesson 8

Titrations &Max Ion Concentration

Review Questions

1. Mg(OH)2 will have the greatest solubility in:

Mg(OH)2 ⇌ Mg2+ + 2OH-

A. NaOH

B. Mg(NO3)2

C. H2O

Ag+ increases solubility by reacting with OH-

No effect solubility

Mg2+ lowers solubility

OH- lowers solubility

D. AgNO3

Review Questions

2. Mg(OH)2 will have the lowest solubility in:

Mg(OH)2 ⇌ Mg2+ + 2OH-

A. 1.0 M NaNO3

B. 1.0 M NaOH

remember: Sr(OH)2 Sr2+ + 2OH-

1.0 M 1.0 M 2.0 M

2.0 M OH- lowers solubility more

1.0 M OH- lowers solubility

No effect

C. 1.0 M Sr(OH)2

Review Questions

3. PbCl2 will have the lowest solubility in:

PbCl2 ⇌ Pb2+ + 2Cl-

A. 1.0 M NaCl

B. 1.0 M MgCl2

C. 1.0 M AlCl3

4.0 M Cl-

3.0 M Cl-

2.0 M Cl-

1.0 M Cl-

D. 2.0 M CaCl2

Maximum Ion Concentration

0.100 M BrO3-

[Ag+]

What is the molarity of [Ag+] just before it precipitates?

AgBrO3(s) ⇌ Ag+ + BrO3-

0.100 M

Ksp = [Ag+][BrO3-]

5.3 x 10-5 = [Ag+][0.100]

[Ag+] = 5.3 x 10-4 M

4. What is the maximum [Ag+] possible in a 0.100M NaBrO3 without forming a

precipitate @ 25 0C.

5. Calculate the maximum number of grams of AgNO3 that will dissolve 100.0 mL of 0.200M AlCl3 without forming a precipitate @ 25 0C.

AgCl(s) ⇌ Ag+ + Cl-

0.600 M

Ksp = [Ag+][Cl-]

1.8 x 10-10 = [Ag+][0.600]

[Ag+] = 3.0 x 10-10 M

= 5.1 x 10-9 g 1 mole

x 169.9 g1 L

x 3.0 x 10-10 moles0.1000 L AgNO3

6. In a titration 3.61 mL of 0.0200M NaI is required to completely precipitate all of the lead II ions in 10.0 mL of saturated PbCl2 solution. Calculate the [Pb2+].

= 0.00361 M

0.0100 L

x 1 mol Pb2+x 0.0200 mol 0.00361 L I-

[Pb2+] =2 mol I-1L

0.0100 L 0.00361 L

0.0200 M? M

Pb2+ + 2I- PbI2