PRACTICE QUESTIONS
5.
Calculate the pH of a buffer solution that contains 0.25 M benzoic acid (C6H5CO2H) and
0.15 M sodium benzoate (C6H5COONa). [Ka = 6.5  10-5 for benzoic acid]
A.
B.
C.
D.
E.
3.97
4.83
4.19
3.40
4.41
6. A solution is prepared by mixing 500. mL of 0.10 M NaOCl and 500. mL of 0.20 M HOCl.
What is the pH of this solution? [Ka(HOCl) = 3.2  10-8]
A. 4.10
B. 7.00
C. 7.19
D.7.49
E. 7.80
7. Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid (HCNO)
and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of solution.
[Ka(HCNO) = 2.0  10-4]
A. 0.97
B. 3.10
C. 4.40
D. 3.70
E. 4.30
8. Calculate the pH of a solution that is 0.410 M in HOCl and 0.050 M in NaOCl.
[Ka(HOCl) = 3.2  10-8]
A. 0.39
B. 3.94
C. 6.58
D. 7.49
E. 8.40
16. You have 500.0 mL of a buffer solution containing 0.20 M acetic acid (CH3COOH) and 0.30
M sodium acetate (CH3COONa). What will the pH of this solution be after the addition of
20.0 mL of 1.00 M NaOH solution? [Ka = 1.8  10-5]
A. 4.41
B. 4.74
C. 4.56
D. 4.92
E. 5.07
17. You have 500.0 mL of a buffer solution containing 0.30 M acetic acid (CH3COOH) and 0.20
M sodium acetate (CH3COONa). What will the pH of this solution be after the addition of
20.0 mL of 1.00 M NaOH solution? [Ka = 1.8  10-5]
A. 4.65
B. 4.71
C. 4.56
D. 4.84
E. 5.07
18. Calculate the percent ionization of cyanic acid, Ka = 2.0  10-4, in a buffer solution that is
0.50 M HCNO and 0.10 M NaCNO.
A.
B.
C.
D.
E.
0.02%
0.10%
0.20%
2.0%
20%
19. In which one of the following solutions will acetic acid have the greatest percent ionization?
A. 0.1 M CH3COOH
B. 0.1 M CH3COOH dissolved in 0.1 M HCl
C. 0.1 M CH3COOH dissolved in 0.2 M HCl
D. 0.1 M CH3COOH plus 0.1 M CH3COONa
E. 0.1 M CH3COOH plus 0.2 M CH3COONa
20. On the basis of the information below, a buffer with a pH = 9 can best be made by using
A. pure NaH2PO4-.
B. H2PO4- + PO43-.
C. H2PO4- + HPO42-.
D. HPO42- + PO43-.
54.Will a precipitate form (yes or no) when 50.0 mL of 1.2  10-3 M Pb(NO3)2 are added to 50.0
mL of 2.0  10-4 M Na2S? If so, identify the precipitate.
A. Yes, the precipitate is PbS.
B. Yes, the precipitate is NaNO3.
C. Yes, the precipitate is Na2S.
D. Yes, the precipitate is Pb(NO3)2.
E. No, a precipitate will not form.
55. Will a precipitate of magnesium fluoride form when 300. mL of 1.1  10-3 M MgCl2 are
added to 500. mL of 1.2  10-3 M NaF? (Ksp (MgF2) = 6.9  10-9)
A. Yes, Q > Ksp
B. No, Q < Ksp
C. No, Q = Ksp
D. Yes, Q < Ksp
56. Will a precipitate of magnesium fluoride form when 200. mL of 1.9  10-3 M MgCl2 are
added to 300. mL of 1.4  10-2 M NaF? (Ksp (MgF2) = 6.9  10-9)
A. Yes, Q > Ksp
B. No, Q < Ksp
C. No, Q = Ksp
D. Yes, Q < Ksp
57. Will a precipitate (ppt) form when 300. mL of 5.0  10-5 M AgNO3 are added to 200. mL of
2.5  10-7 M NaBr? Answer yes or no, and identify the precipitate if there is one.
A. Yes, the ppt is AgNO3(s).
B. Yes, the ppt is AgBr(s).
C. Yes, the ppt is NaBr(s).
D. Yes, the ppt is NaNO3(s).
E. No, a precipitate will not form.
1.Which of the following reactions is not readily explained by the Arrhenius concept of acids and bases?
A)
B)
C)
D)
E)
HCl(g) + NH3(g)  NH4Cl(s)
HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l)
HClO4(aq) + H2O(l)  H3O+(aq) + ClO4(aq)
HC2H3O2(aq) + H2O(l)
H3O+(aq) + C2H3O2(aq)
H3O+(aq) + OH(aq)  2H2O(l)
ANS: A
2. Which of the following statements is/are consistent with the Arrhenius concept of acids and
bases?
1.
2.
3.
A)
B)
C)
D)
E)
An Arrhenius acid will increase the concentration of hydronium ion in an
aqueous or nonaqueous solvent.
All Arrhenius acids are strong electrolytes in water.
All strong acid-strong base reactions have the same heat of reaction (H) per
mole of water formed.
1 only
2 only
3 only
1 and 3
1, 2 and 3
ANS: C
3. Which of the following statements does not describe a characteristic of an Arrhenius acid?
A) An Arrhenius acid reacts with an Arrhenius base to produce a salt.
B) An Arrhenius acid turns red litmus blue.
C) An Arrhenius acid is an electrolyte.
D) An Arrhenius acid reacts with CaCO3 to produce CO2.
E) An Arrhenius acid tastes sour.
ANS: B
4. Which of the following species is not capable of acting as an Arrhenius acid in aqueous solution?
A)
B)
C)
D)
E)
Br–
HF
H2SO3
H3O
HNO3
ANS: A
5. Which of the following species is not capable of acting as an Arrhenius acid in aqueous solution?
A)
B)
C)
D)
E)
CHCl3
HNO3
H2SO4
H3O
HClO4
ANS: A
6. Which of the following statements is correct concerning the neutralization of sulfurous acid by a
strong base?
2OH–(aq) + H2SO3(aq) SO32–(aq) + 2H2O(l)

A)
B)
C)
D)
E)
H2SO3 is both an Arrhenius acid and a Brønsted–Lowry acid.
H2SO3 is a Brønsted–Lowry acid, but not an Arrhenius acid.
H2SO3 is neither an Arrhenius acid nor a Brønsted–Lowry acid.
H2SO3 is an Arrhenius acid, but not a Brønsted–Lowry acid.
H2SO3 is a Lewis base.
ANS: A
7. Which of the following statements is/are consistent with the Brønsted-Lowry concept of acids
and bases?
1.
2.
3.
A conjugate acid-base pair may differ by only one proton.
A base is defined as a hydroxide ion donor.
Brønsted-Lowry acid-base reactions are restricted to aqueous solutions.
A)
B)
C)
D)
E)
1 only
2 only
3 only
1 and 2
1, 2, and 3
ANS: A
8. Which are the Brønsted–Lowry bases in the following equilibrium?
CH3COO–(aq) + H2O(l)
A)
B)
C)
D)
E)
CH3COOH(aq) + OH–(aq)
CH3COO– and OH–
H2O and OH–
H2O, CH3COOH, and OH–
CH3COO– and CH3COOH
H2O and CH3COOH
ANS: A
9. Which of the following pairs of species is not a conjugate acid–base pair?
A) HOCl, OCl–
B) HNO2, NO2+
C) O2–, OH–
D) HSO4–, SO42–
E) H2CO3, HCO3–
ANS: B
10. What is a conjugate acid–base pair for the following equilibrium?
H2O(l) + HPO42–(aq)
A)
B)
C)
D)
E)
H2PO4–(aq) + OH–(aq)
H2O is an acid and HPO42– is its conjugate base.
HPO42– is an acid and OH– is its conjugate base.
H2O is an acid and OH– is its conjugate base.
HPO42– is an acid and H2PO4– is its conjugate base.
HPO42– is an acid and H2O is its conjugate base.
ANS: C
11. What is the conjugate base of H2PO4–(aq)?
A) PO43–
B) H3O+
C) HPO4
D) H3P
E) H3PO4
ANS: C
7.For the equilibrium that exists in an aqueous solution of nitrous acid (HNO2, a weak acid), the
equilibrium-constant expression is
A)
K=
.
K=
.
B)
C)
K=
.
D) K = [H+][NO2–].
E) none of these
ANS: C
8. Consider the Ka values for the following acids:
Cyanic acid, HOCN, 3.5  10–4
Formic acid, HCHO2, 1.7  10–4
Lactic acid, HC3H5O3, 1.3  10–4
Propionic acid, HC3H5O2, 1.3  10–5
Benzoic acid, HC7H5O2, 6.3  10–5
Which has the strongest conjugate base?
A)
B)
C)
D)
E)
propionic acid
benzoic acid
lactic acid
formic acid
cyanic
ANS: A
9. Consider the Ka values for the following acids:
Cyanic acid, HOCN, 3.5  10–4
Formic acid, HCHO2, 1.7  10–4
Lactic acid, HC3H5O3, 1.3  10–4
Propionic acid, HC3H5O2, 1.3  10–5
Benzoic acid, HC7H5O2, 6.3  10–5
Given initially equimolar soutions of each weak acid, which solution will have the highest
hydronium ion concentration once equilibrium is established?
A) cyanic acid
B) benzoic acid
C) lactic acid
D) formic acid
E) propionic acid
ANS: A
10. Rank acetic acid (HC2H3O2), hydrocyanic acid (HOCN), and hydrofluoric acid (HF) in order of
increasing strength.
Acid
HC2H3O2
HOCN
HF
A)
B)
C)
D)
E)
Ka
1.8  10–5
3.5  10–4
6.8  10–4
HC2H3O2 < HOCN < HF
HOCN < HC2H3O2 < HF
HOCN < HF < HC2H3O2
HF < HOCN < HC2H3O2
HF < HC2H3O2 < HOCN
ANS: A
4.What is the solubility product expression for Al(OH)3?
A) Ksp = [Al3+][3OH–]
B) Ksp = 3[Al3+][OH–]3
C) Ksp = [Al3+][OH–]3
D) Ksp = [Al3+][3OH–]3
E) Ksp = [Al3+][OH–]
ANS: C
5. What is the solubility product expression for Th(IO3)4?
A) Ksp = [Th4+][4IO3–]4
B) Ksp = [Th4+][IO3–]
C) Ksp = [Th][IO3]4
D) Ksp = [Th4+][IO3–]4
E) Ksp = [Th4+][IO3–]
ANS: D
6. What is the solubility product expression for Zn3(PO4)2?
A) Ksp = [Zn32+][(PO43–)2]
B) Ksp = [3Zn2+]3[2PO43–]2
C) Ksp = [Zn2+][2PO43–]
D) Ksp = [Zn3+]2[PO42–]3
E) Ksp = [Zn2+]3[PO43–]2
ANS: E
7. What is the solubility product expression for mercury(I) iodide, Hg2I2?
A)
B)
C)
D)
E)
Ksp = [Hg22+][2I–]2
Ksp = [Hg22+][I–]2
Ksp = [Hg22+][2I– ]
Ksp = [Hg2][I2]
Ksp = [Hg+]2[I–]2
ANS: B
8. What is the solubility product expression for La2(CO3)3?
A) Ksp = [2La3+]2[3CO32–]3
B) Ksp = [La2+]2[CO32–]3
C) Ksp = [2La3+]2[CO32–]3
D) Ksp = [2La3+][3CO32–]
E) Ksp = [La3+]2[CO32–]3
ANS: E
9. What is the solubility product expression for Pb3(PO4)4?
A) Ksp = [Pb3+]4[PO44–]3
B) Ksp = [3Pb3+][4PO43–]
C) Ksp = [3Pb3+]3[4PO43–]4
D) Ksp = [Pb2+]3[PO43–]2
E) Ksp = [Pb4+]3[PO43–]4
ANS: E
24.Which of the following salts has the lowest molar solubility?
A) SrCO3 (Ksp = 9.3  10–10)
B) MnS (Ksp = 2.5  10–10)
C) BaF2 (Ksp = 1.0  10–6)
D) BaSO4 (Ksp = 1.1  10–10)
E) AgCl (Ksp = 1.8  10–10)
ANS: D
25. Rank the following salts in order of increasing molar solubility.
Salt
BaSO4
AgCl
BaCO3
CdS
PbSO4
A)
B)
C)
D)
E)
Ksp
1.1  10–10
1.8  10–10
9.1  10–9
8  10–27
1.8  10–8
CdS < AgCl < BaSO4 < BaCO3 < PbSO4
CdS < AgCl < BaCO3 < BaSO4 < PbSO4
CdS < BaSO4 < AgCl < BaCO3 < PbSO4
PbSO4 < BaCO3 < AgCl < BaSO4 < CdS
PbSO4 < BaCO3 < BaSO4 < AgCl < CdS
ANS: C
26. A saturated solution of which of the following salts will have the lowest molar concentration of
chromate ion?
A)
B)
C)
D)
E)
BaCrO4 (Ksp = 2.1  10-10)
CuCrO4 (Ksp = 3.6  10-6)
Ag2CrO4 (Ksp = 1.2  10-12)
Hg2CrO4 (Ksp = 2.0  10-9)
Tl2CrO4 (Ksp = 9.8  10-13)
ANS: A
27. A saturated solution of which of the following salts will have the greatest molar concentration of
silver ion?
A)
B)
C)
D)
E)
Ag2S (Ksp = 8  10-51)
AgCl (Ksp = 1.8  10-10)
Ag2CrO4 (Ksp = 1.2  10-12)
Ag2CO3 (Ksp = 8.1  10-12)
Ag4Fe(CN)6 (Ksp = 8.5  10-45)
ANS: D
28. What is the solubility (in g/L) of aluminum hydroxide at 25°C? The solubility product constant
for aluminum hydroxide is 4.6  10–33 at 25°C.
A) 3.6  10–31 g/L
B) 8.2  10–10 g/L
C) 2.8  10–7 g/L
D) 5.3  10–15 g/L
E) 1.8  10–31 g/L
ANS: C
10. What is the solubility product expression for Sn(IO3)2?
A) Ksp = [Sn2+][IO3–]2
B) Ksp = [Sn4+][2IO32–]2
C) Ksp = [Sn2+][2IO3–]
D) Ksp = [Sn4+][IO32–]2
E) Ksp = [Sn2+][2IO3–]2
ANS: A
ANS: D
14.
What is the relationship between molar solubility (s) and Ksp for calcium fluoride?
A)
B)
C)
D)
E)
ANS: A
15. What is the correct mathematical expression for finding the molar solubility (s) of Sn(OH)2?
A) 2s3 = Ksp
B) 4s3 = Ksp
C) 108s5 = Ksp
D) 2s2 = Ksp
E) 8s3 = Ksp
ANS: B
16. The concentration of calcium carbonate in a saturated aqueous solution of the salt at 25°C is
6.71  10 5 M. What is the Ksp of this sparingly soluble salt?
A) 4.50  10 9
B) 1.21  10 12
C) 5.47  10 16
D) 8.19  10 3
E) 4.06  10 2
ANS: A
17. The solubility of strontium carbonate in water at 25°C is 4.50  10 3 g/L. What is the Ksp of this
sparingly soluble salt?
A)
B)
C)
D)
E)
9.30  10 10
1.13  10 13
2.34  10 17
5.52  10 3
3.12  10 2
ANS: A
18. After mixing an excess PbCl2 with a fixed amount of water, it is found that the equilibrium
concentration of Pb2+ is 1.6  10–2 M. What is Ksp for PbCl2?
A) 4.0  10–6
B) 1.6  10–5
C) 2.5  10–4
D) 4.8  10–2
E) 1.0  10–6
ANS: B
19. The solubility of lead(II) sulfate is 4.0  10–2 g/L. What is the solubility product constant for
lead(II) sulfate?
A) 1.7  10–8
B) 1.3  10–4
C) 1.6  10–3
D) 4.6  10–15
E) 8.9  10–12
ANS: A
20. The solubility of silver(I) carbonate is 3.6  10–2 g/L. What is the solubility product constant for
silver(I) carbonate?
A) 4.4  10–15
B) 8.9  10 12
C) 1.7  10–8
D) 1.3  10–4
E) 1.3  10–3
ANS: B
21. The hydroxide ion concentration of a saturated solution of Fe(OH)2 is 1.16  10 5 M. What is the
solubility product constant for Fe(OH)2?
A) 7.80  10 16
B) 6.24  10 15
C) 1.56  10 15
D) 3.41  10 3
E) 2.26  10 2
ANS: A.