12) The concentration of fluoride ions in a saturated solution of barium fluoride is __________ M. The
solubility product constant of BaF2 is 1.7 × 10-6.
A) 3.8 × 10-4
B) 3.0 × 10-3
C) 1.5 × 10-2
D) 7.5 × 10-3
E) 1.4 × 10-4
13) The concentration of iodide ions in a saturated solution of silver iodide is __________ M. The
solubility product constant of AgI is 8.3 × 10-17.
A) 3.8 × 10-11
B) 3.0 × 10-10
C) 9.1 × 10-9
D) 3.5 × 10-9
E) 1.4 × 10-8
14) The solubility of lead (II) chloride (PbCl2) is 1.6 × 10-2 M. What is the Ksp of PbCl2?
A) 5.0 × 10-4
B) 4.1 × 10-6
C) 3.1 × 10-7
D) 1.6 × 10-5
E) 1.6 × 10-2
15) The solubility of manganese (II) hydroxide (Mn(OH)2) is 2.2 × 10-5 M. What is the Ksp of
MnOH)2?
A) 1.1 × 10-14
B) 4.3 × 10-14
C) 2.1 × 10-14
D) 4.8 × 10-10
E) 2.2 × 10-5
16) Determine the Ksp for magnesium hydroxide (Mg(OH)2) where the solubility of Mg(OH)2
is 1.4 × 10-4 M.
A) 2.7 × 10-12
B) 1.1 × 10-11
C) 2.0 × 10-8
D) 3.9 × 10-8
E) 1.4 × 10-4
17) Calculate the maximum concentration (in M) of silver ions (Ag+) in a solution that contains 0.025 M
of CO32-. The Ksp of Ag2CO3 is 8.1 × 10-12.
A) 1.8 × 10-5
B) 1.4 × 10-6
C) 2.8 × 10-6
D) 3.2 × 10-10
E) 8.1 × 10-12
18) Calculate the maximum concentration (in M) of magnesium ions (Mg+2) in a solution that contains
0.025 M of CO32-. The Ksp of MgCO3 is 3.5 × 10-8.
A) 1.8 × 10-5
B) 1.4 × 10-6
C) 2.8 × 10-6
D) 3.2 × 10-10
E) 8.1 × 10-12
19) What is the solubility (in M) of PbCl2 in a 0.15 M solution of HCl? The Ksp of PbCl2 is 1.6 × 10-5.
A) 2.0 × 10-3
B) 1.1 × 10-4
C) 1.8 × 10-4
D) 7.1 × 10-4
E) 1.6 × 10-5
20) The Ksp for Zn(OH)2 is 5.0 × 10-17. Determine the molar solubility of Zn(OH)2 in a buffer solution
with a pH of 11.5.
A) 5.0 × 106
B) 1.2 × 10-12
C) 1.6 × 10-14
D) 5.0 × 10-12
E) 5.0 × 10-17
17.3 Algorithmic Questions
1) Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO2) and 0.205 M in formic
acid (HCO2H). The Ka of formic acid is 1.77 × 10-4.
A) 3.910
B) 3.587
C) 13.84
D) 10.10
E) 4.963
2) Calculate the percent ionization of formic acid (HCO2H) in a solution that is 0.311 M in formic acid
and 0.189 M in sodium formate (NaHCO2). The Ka of formic acid is 1.77 × 10-4.
A) 37.8
B) 0.0937
C) 11.3
D) 1.06 × 10-3
E) 3.529
3) Calculate the percent ionization of formic acid (HCO2H) in a solution that is 0.219 M in formic acid.
The Ka of formic acid is 1.77 × 10-4.
A) 3.94 × 10-5
B) 0.0180
C) 2.84
D) 0.280
E) 12.2
4) Calculate the pH of a solution that is 0.210 M in nitrous acid (HNO2) and 0.290 M in potassium
nitrite (KNO2). The acid dissociation constant of nitrous acid is 4.50 × 10-4.
A) 3.487
B) 3.210
C) 13.86
D) 10.51
E) 4.562
5) Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO2)
and 0.278 M in potassium nitrite (KNO2). The acid dissociation constant of nitrous acid is 4.50 × 10-4.
A) 55.6
B) 0.162
C) 15.5
D) 2.78 × 10-3
E) 3.448
6) Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid
dissociation constant of nitrous acid is 4.50 × 10-4.
A) 1.12 × 10-4
B) 0.0450
C) 4.25
D) 0.342
E) 5.53
7) What is the pH of a buffer solution that is 0.211 M in lactic acid and 0.111 M in sodium lactate? The
Ka of lactic acid is 1.4 × 10-4.
A) 14.28
B) 10.43
C) 5.48
D) 3.57
E) 4.13
8) What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO) and 0.333 M in
sodium hypochlorite? The Ka of hypochlorous acid is 3.8 × 10-8.
A) 13.88
B) 6.46
C) 8.49
D) 7.30
E) 7.54
9) A solution is prepared by dissolving 0.23 mol of hydrofluoric acid and 0.27 mol of sodium fluoride in
water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this buffer solution
causes the pH to drop slightly. The pH does not decrease drastically because the HCl reacts with the
__________ present in the buffer solution. The Ka of hydrofluoric acid is 1.36 × 10-3.
A) H2O
B) H3O+
C) fluoride ion
D) hydrofluoric acid
E) This is a buffer solution: the pH does not change upon addition of acid or base.
10) A solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide in
water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of NaOH to this buffer solution
causes the pH to increase slightly. The pH does not increase drastically because the NaOH reacts with
the __________ present in the buffer solution. The Ka of hydrazoic acid is 1.9 × 10-5.
A) H2O
B) H3O+
C) azide
D) hydrazoic acid
E) This is a buffer solution: the pH does not change upon addition of acid or base.
11) The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 × 10-5) and 0.182 M sodium
acetate is __________.
A) 4.102
B) 5.407
C) 8.593
D) 8.370
E) 9.898
12) Consider a solution containing 0.100 M fluoride ions and 0.126 M hydrogen fluoride. The
concentration of fluoride ions after the addition of 4.00 mL of 0.0100 M HCl to 25.0 mL of this solution
is __________ M.
A) 0.0862
B) 0.0876
C) 0.0980
D) 0.0848
E) 0.00253
13) Consider a solution containing 0.100 M fluoride ions and 0.126 M hydrogen fluoride. The
concentration of hydrogen fluoride after addition of 8.00 mL of 0.0100 M HCl to 25.0 mL of this
solution is __________ M.
A) 0.0979
B) 0.0930
C) 0.129
D) 0.123
E) 0.00976
14) The Ka of acetic acid is 1.76 × 10-5. The pH of a buffer prepared by combining 45.0 mL of 1.00 M
potassium acetate and 50.0 mL of 1.00 M acetic acid is __________.
A) 1.705
B) 0.851
C) 3.406
D) 4.709
E) 2.383
15) The Kb of ammonia is 1.76 × 10-5. The pH of a buffer prepared by combining 50.0 mL of 1.00 M
ammonia and 50.0 mL of 1.00 M ammonium nitrate is __________.
A) 4.632
B) 9.246
C) 4.742
D) 9.372
E) none of the above
16) Calculate the pH of a solution prepared by dissolving 0.270 mol of formic acid (HCO2H) and 0.230
mol of sodium formate (NaCO2H) in water sufficient to yield 1.00 L of solution. The Ka of formic acid
is 1.77 × 10-4.
A) 2.099
B) 10.318
C) 3.682
D) 2.307
E) 3.952
17) Calculate the pH of a solution prepared by dissolving 0.850 mol of NH3 and 0.350 mol of NH4Cl in
water sufficient to yield 1.00 L of solution. The Kb of ammonia is 1.77 × 10-5.
A) 5.137
B) 4.367
C) 9.633
D) 8.781
E) 8.863
18) Calculate the pH of a solution prepared by dissolving 0.350 mol of benzoic acid (C7H5O2H) and
0.250 mol of sodium benzoate (NaC7H5O2) in water sufficient to yield 1.00 L of solution. The Ka of
benzoic acid is 6.50 × 10-5.
A) 4.333
B) 4.041
C) 9.959
D) 9.667
E) 5.190
19) How many milliliters of 0.0850 M NaOH are required to titrate 25.0 mL of 0.0720 M HBr to the
equivalence point?
A) 21.2
B) 0.245
C) 3.92
D) 0.153
E) 29.5
20) A 25.0 mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution. What is the
pH at the equivalence point? The Ka of hydrazoic acid is 4.50 × 10-4.
A) 11.72
B) 9.28
C) 4.72
D) 7.00
E) 8.80
21) A 25.0-mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the
pH before any base is added? The Ka of butanoic acid is 1.5 × 10-5.
A) 2.83
B) 1.5 × 10-3
C) 4.82
D) 4.00
E) 1.0 × 104
22) A 25.0 mL sample of 0.150 M hypochlorous acid is titrated with a 0.150 M NaOH solution. What is
the pH after 26.0 mL of base is added? The Ka of hypochlorous acid is 3.0 × 10-8.
A) 2.54
B) 11.47
C) 7.00
D) 7.51
E) 7.54
23) How many milliliters of 0.120 M NaOH are required to titrate 50.0 mL of 0.0998 M butanoic acid to
the equivalence point? The Ka of butanoic acid is 1.5 × 10-5.
A) 4.90
B) 50.0
C) 41.6
D) 60.1
E) 4.65
24) A 25.0-mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution. What is the
pH after 13.3 mL of base is added? The Ka of hydrazoic acid is 1.9 × 10-5.
A) 4.45
B) 1.34
C) 3.03
D) 4.78
E) 4.66
25) A 25.0 mL sample of 0.723 M HClO4 is titrated with a 0.273 M KOH solution. The H3O+
concentration after the addition of 60.0 mL of KOH is __________ M.
A) 0.0181
B) 0.430
C) 0.0200
D) 0.273
E) none of the above
26) A 25.0 mL sample of an acetic acid solution is titrated with a 0.175 M NaOH solution. The
equivalence point is reached when 26.6 mL of the base is added. The concentration of acetic acid in the
sample was __________ M.
A) 0.365
B) 0.175
C) 0.119
D) 0.186
E) none of the above
27) A 25.0 mL sample of an HCl solution is titrated with a 0.139 M NaOH solution. The equivalence
point is reached with 25.3 mL of base. The concentration of HCl is __________ M.
A) 11.7
B) 0.00352
C) 0.141
D) 0.0352
E) 0.139
28) The pH of a solution prepared by mixing 45.0 mL of 0.183 M KOH and 25.0 mL of 0.145 M HCl is
__________.
A) 1.314
B) 1.181
C) 0.00824
D) 12.819
E) 12.923
29) The pH of a solution prepared by mixing 55.0 mL of 0.183 M KOH and 30.0 mL of 0.145 M
HC2H3O2 is __________.
A) 9.97
B) 7.74
C) 1.172
D) 12.828
E) none of the above
30) What is the molar solubility of silver chloride (AgCl) in water? The solubility-product constant for
AgCl is 1.8 × 10-10 at 25°C.
A) 9.0 × 10-11
B) 3.6 × 10-10
C) 9.74
D) 1.9 × 10-5
E) 1.3 × 10-5
31) What is the molar solubility of silver sulfate (Ag2SO4) in water? The solubility-product constant
for Ag2SO4 is 1.5 × 10-5 at 25°C.
A) 1.9 × 10-3
B) 2.5 × 10-2
C) 5.5 × 10-3
D) 1.6 × 10-2
E) 5.0 × 10-6
32) In which aqueous system is Pbl2 least soluble?
A) H2O
B) 0.5 M HI
C) 0.2 M HI
D) 1.0 M HNO3
E) 0.8 M KI
33) A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba2+. When the concentration
of F– exceeds __________ M, BaF2 will precipitate. Neglect volume changes. For BaF2,
Ksp = 1.7 × 10-6.
A) 5.9 × 10-5
B) 1.1 × 10-2
C) 2.4 × 10-8
D) 2.7 × 10-3
E) 1.2 × 10-4
17.4 Short Answer Questions
1) Calculate the pH of a buffer that contains 0.270 M hydrofluoric acid (HF) and 0.180 M cesium
fluoride (CsF). The Ka of hydrofluoric acid is 6.80 × 10-4.
2) Calculate the pH of a buffer solution that contains 0.820 grams of sodium acetate and 0.010 moles of
acetic acid in 100 ml of water. The Ka of acetic acid is 1.77 × 10-5.
3) Suppose you have just added 100.0 ml of a solution containing 0.5000 moles of acetic acid per liter to
400.0 ml of 0.5000 M NaOH. What is the final pH? The Ka of acetic acid is 1.77 × 10-5.
4) Suppose you have just added 200.0 ml of a solution containing 0.5000 moles of acetic acid per liter to
100.0 ml of 0.5000 M NaOH. What is the final pH? The Ka of acetic acid is 1.77 × 10-5.
5) 200.0 ml of a solution containing 0.5000 moles of acetic acid per liter is added to 200.0 ml of 0.5000
M NaOH. What is the final pH? The Ka of acetic acid is 1.77 × 10-5.
6) In general, the solubility of a slightly soluble salt is __________ by the presence of a second solute
that furnishes a common ion.
7) Although CaCO3 has a relatively small solubility product, it is quite soluble in the presence of
__________.
8) An assembly of a metal ion and the Lewis bases bonded to it is called a __________.
9) Metal oxides and hydroxides that are relatively insoluble in neutral water, but are soluble in both
strongly acidic and strongly basic solutions are said to be __________.
10) __________ analysis determines only the presence or absence of a particular metal ion, whereas
__________ analysis determines how much of a given substance is present.
17.5 True/False Questions
1) The extent of ionization of a weak electrolyte is increased by adding to the solution a strong
electrolyte that has an ion in common with the weak electrolyte.
2) For any buffer system, the buffer capacity depends on the amount of acid and base from which the
buffer is made.
3) The solubility product of a compound is numerically equal to the product of the concentration of the
ions involved in the equilibrium, each multiplied by its coefficient in the equilibrium reaction.
4) The solubility of a slightly soluble salt is decreased by the presence of a second solute that provides a
common ion to the system.
5) The solubility of slightly soluble salts containing basic anions is proportional to the pH of the
solution.