Name: __________________________ Date: _____________
1. For which of the following equilibria does Kc correspond to an acid-ionization constant,
Ka?
A) NH (aq) + H O+(aq)
NH +(aq) + H O(l)
3
B)
3
4
+
NH4 (aq) + H2O(l)
NH3(aq) + H3O (aq)
C) NH (aq) + OH (aq)
4
D) HF(aq) + OH–(aq)
+
E)
2
+
–
F–(aq) + H2O(l)
NH3(aq) + H2O(l)
H2O(l) + F–(aq)
HF(aq) + OH–(aq)
2. For which of the following equilibria does Kc correspond to the acid-ionization constant,
Ka, of HC2O4–?
A) H C O (aq) + H O(l)
H O+(aq) + HC O –(aq)
2
B)
C)
D)
E)
2
4
HC2O4–(aq)
HC2O4–(aq)
HC2O4–(aq)
HC2O4–(aq)
2
3
+ H2O(l)
+
+ H3O (aq)
+ H2O(l)
+ OH–(aq)
2
4
–
H2C2O4(aq) + OH (aq)
H2C2O4(aq) + H2O(l)
H3O+(aq) + C2O42–(aq)
C2O42–(aq) + H2O(l)
3. 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 of the following is the strongest acid?
A) cyanic acid
B) formic acid
C) lactic acid
D) propionic acid
E) benzoic acid
Page 1
4. Rank acetic acid (HC2H3O2), hydrocyanic acid (HOCN), and hydrofluoric acid (HF) in
order of increasing strength.
Acid
Ka
HC2H3O2 1.8 × 10-5
HOCN
3.5 × 10-4
HF
6.8 × 10-4
A) HC2H3O2 < HOCN < HF
B) HOCN < HC2H3O2 < HF
C) HF < HOCN < HC2H3O2
D) HF < HC2H3O2 < HOCN
E) HOCN < HF < HC2H3O2
5. What is the percent ionization of a 1.4 M HC2H3O2 solution (Ka = 1.8
A) 0.50%
B) 0.36%
C) 0.30%
D) 0.18%
E) 2.2%
10-5) at 25°C?
6. A 0.037 M solution of a weak monoprotic acid is 2.6% ionized at 25ºC. What is the
acid-ionization constant, Ka, for this acid?
A) 2.6 × 10–2
B) 3.7 × 10–2
C) 9.6 × 10–4
D) 6.8 × 10–4
E) 2.6 × 10–5
7. A 1.0 M solution of a weak monoprotic acid is 0.50% ionized. What is the
acid-ionization constant, Ka, of the weak acid?
A) 5.0 × 10-1
B) 5.0 × 10-3
C) 2.5 × 10-5
D) 2.5 × 10-6
E) 2.5 × 10-7
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8. What is the hydronium-ion concentration of a 0.30 M solution of HCN (Ka = 4.9 × 10-10)
at 25ºC?
A) 2.2 × 10-6 M
B) 3.4 × 10-6 M
C) 1.2 × 10-5 M
D) 4.0 × 10-5 M
E) 1.7 × 10-4 M
9. Hypobromous acid, HOBr, has an acid-ionization constant of 2.5 × 10-9 at 25ºC. What is
the pOH of a 0.62 M HOBr solution?
A) 4.40
B) 3.86
C) 5.19
D) 9.60
E) 10.14
10. What is the pH of a solution prepared by dissolving 0.0298 mol of chloroacetic acid,
HC2H2O2Cl) in 1.80 L of water? For chloroacetic acid, Ka = 1.4 10–3.
A) 1.78
B) 2.38
C) 2.32
D) 11.62
E) 12.22
11. What is the hydronium-ion concentration in a 0.027 M solution of carbonic acid,
H2CO3? For carbonic acid, Ka1 = 4.2 10–7 and Ka2 = 4.8 10–11.
A) 5.3  10–5 M
B) 2.7  10–2 M
C) 4.8  10–11 M
D) 1.1  10–4 M
E) 4.2  10–7 M
12. What is the hydronium-ion concentration of a 0.320 M oxalic acid, H2C2O4, solution?
For oxalic acid, Ka1 = 5.6 10–2 and Ka2 = 5.1 10–5.
A) 1.1  10–1 M
B) 4.0  10–3 M
C) 1.3  10–1 M
D) 4.0  10–3 M
E) 1.0  10–7 M
Page 3
13. What is the concentration of C2O42– in a 0.250 M oxalic acid, H2C2O4, solution? For
oxalic acid, Ka1 = 5.6 10–2 and Ka2 = 5.1 10–5.
A) 1.2  10–1 M
B) 3.6  10–3 M
C) 9.4  10–2 M
D) 3.5  10–3 M
E) 5.1  10–5 M
14. What is the pH of a 0.47 M solution of methylamine (CH3NH2, Kb = 4.4
25oC?
A) 12.15
B) 0.33
C) 1.85
D) 13.67
E) 5.49
15. What is the pOH of a 0.10 M solution of pyridine (Kb = 1.4
A) 11.34
B) 4.93
C) 8.85
D) 3.93
E) 2.00
10–4) at
10-9) at 25ºC?
16. What is the percent ionization at equilibrium in a 0.77 M solution of dimethylamine,
(CH3)2NH (Kb = 5.1 10–4), at 25oC?
A) 77%
B) 2.5%
C) 2.0%
D) 100%
E) 0.066%
17. Which of the following equilibria best represents the hydrolysis reaction that occurs in
an aqueous solution of KNO2?
A) K+(aq) + H O(l)
KOH(aq) + H+(aq)
2
B)
–
NO2 (aq) + H2O(l)
HNO2(aq) + OH–(aq)
C) K+(aq) + NO –(aq) + H O(l)
KOH(aq) + HNO2(aq)
2
2
D) NO –(aq) + H O(l)
HNO3(aq) + 2H+(aq)
2
2
E) NO –(aq) + H O+(aq)
HNO (aq) + H O(l)
2
3
2
Page 4
2
18. Which of the following salts will produce a neutral solution when added to pure water?
A) LiHCO3
B) Na2SO4
C) RbNO2
D) NH4NO3
E) KNO3
19. Which of the following salts will produce an acidic solution when added to pure water?
A) Li2O
B) NaBr
C) KHSO4
D) Rb2CO3
E) CsNO3
20. The Ka for propionic acid is 1.3
A) 1.3 10–19
B) 1.3 109
C) 7.7 104
D) 7.7 10–10
E) 1.3  10–5
10–5. What is Kb for the propionate ion?
21. What is the hydroxide-ion concentration in a 0.10 M solution of Na2CO3? For
carbonic acid, Ka1 = 4.2 10–7 and Ka2 = 4.8 10–11. (Kw = 1.0 10–14)
A) 4.6 10-3 M
B) 2.0 10-4 M
C) 4.9 10-5 M
D) 2.2 10-6 M
E) 4.2  10-9 M
22. What is the pH of a solution prepared by adding 2.03 g of potassium nitrite to 145 mL
of water? Ka of HNO2 is 4.5 × 10-4.
A) 7.00
B) 2.08
C) 5.72
D) 8.28
E) 11.92
Page 5
23. Which of the following substances, if added to a 0.10 M HC2H3O2 solution, would not
increase the hydronium-ion concentration?
A) NaHSO4(s)
B) 1 M HCl
C) HF(l)
D) Na2CO3(s)
E) H2C2O4(s)
24. Which of the following is the most effective buffer system for a pH value of 4.45?
A) H2CO3/HCO3– (Ka1 for H2CO3 is 4.3 10–7.)
B) HCO3–/CO32– (Ka2 for H2CO3 is 4.8 10–11.)
C) H2S/HS– (Ka1 for H2S is 8.9 10–8.)
D) HC2O4–/C2O42– (Ka2 for H2C2O4 is 5.1 10–5.)
E) H3PO4/H2PO4– (Ka1 for H3PO4 is 6.9  10–3.)
25. A weak acid, HF, is in solution with dissolved sodium fluoride, NaF. If HCl is added,
which ion will react with the extra hydrogen ions from the HCl to keep the pH from
changing?
A) OH–
B) Na+
C) F–
D) Na–
E) none of these
26. What mass of sodium hydroxide must be added to 30.0 mL of 0.598 M acetic acid in
order to create a buffer with a pH of 4.54? Ka for acetic acid is 1.8 × 10-5.
A) 0.000035 g
B) 0.28 g
C) 0.72 g
D) 25 g
E) 1.0 g
27. What is the pH at the equivalence point of the titration of a strong acid with a strong
base?
A) 3.9
B) 4.5
C) 7.0
D) 8.2
E) none of these
Page 6
28. The titration curve shown below represents the titration of a weak acid with a strong
base. Which point represents the equivalence point?
A)
B)
C)
D)
E)
I
II
III
IV
V
29. A solution contains 10. mmol of H3PO4 and 5.0 mmol of NaH2PO4. How many
milliliters of 0.10 M NaOH must be added to reach the second equivalence point of the
titration of the H3PO4 with NaOH?
A) 250 mL
B) 150 mL
C) 1.0 × 102 mL
D) 50 mL
E) 2.0 × 102 mL
30. A 25.00-mL sample of propionic acid, HC3H5O2, of unknown concentration was titrated
with 0.127 M KOH. The equivalence point was reached when 39.32 mL of base had
been added. What is the hydroxide-ion concentration at the equivalence point? Ka for
propionic acid is 1.3 10-5 at 25°C.
A) 1.5 10-9 M
B) 1.0 10-7 M
C) 7.7 10-6 M
D) 1.1 10-5 M
E) 1.0  10-3 M
Page 7
31. The titration curve shown below represents the titration of a weak base with a strong
acid. Which point represents the equivalence point?
A)
B)
C)
D)
E)
I
II
III
IV
V
32. What is the hydronium-ion concentration of a solution that is formed by combining 600.
mL of 0.20 M NaOH with 400. mL of 0.70 M HNO3 at 25ºC?
A) 0.070 M
B) 0.16 M
C) 0.45 M
D) 0.020 M
E) 0.60 M
33. Which of the following salts forms an acidic aqueous solution?
A) NaCl
B) NaCN
C) CaCl2
D) FeCl3
E) NaNO2
Page 8
34. What is Kc at 25ºC for the following equilibrium?
CH3NH3+(aq) + H2O(l)
CH3NH2(aq) + H3O+(aq)
Kb (CH3NH2) = 4.4 10-4 at 25ºC.
A) 2.3 10-11
B) 4.4 10-10
C) 4.4 10-4
D) 4.4 104
E) 2.3  103
35. What is the solubility product expression for Ca3(PO4)2?
A) Ksp = [Ca32+][(PO43–)2]
B) Ksp = [Ca2+][2PO43–]
C) Ksp = [Ca2+]3[PO43–]2
D) Ksp = [3Ca2+]3[2PO43–]2
E) Ksp = [Ca3+]2[PO42–]3
36. What is the correct mathematical expression for finding the molar solubility (s) of
Sn(OH)2?
A) 2s2 = Ksp
B) 2s3 = Ksp
C) 108s5 = Ksp
D) 4s3 = Ksp
E) 8s3 = Ksp
37. The hydroxide-ion concentration of a saturated solution of Cu(OH)2 is 8.0
What is the solubility product constant for Cu(OH)2?
A) 6.4 10–20
B) 1.3 10–19
C) 2.6 10–19
D) 5.2 10–19
E) 2.1  10–18
10–7 M.
38. What is the solubility (in g/L) of calcium fluoride at 25ºC? The solubility product
constant for calcium fluoride is 3.4 10–11 at 25ºC.
A) 1.3 10–9 g/L
B) 2.7 10–9 g/L
C) 0.00046 g/L
D) 0.016 g/L
E) 0.094 g/L
Page 9
39. What is the hydroxide-ion concentration of a saturated solution of Mg(OH)2? For
Mg(OH)2, Ksp = 1.8 10–11.
A) 1.7 10–4 M
B) 3.3 10–4 M
C) 4.2 10–6 M
D) 1.0 10–3 M
E) 1.0  10–7 M
40. The insoluble salts AV, B2W, C2X3, DY2, and EZ3, which were formed from the metal
ions A+, B+, C3+, D2+, and E3+ and the nonmetals V1–, W2–, X2–, Y1–, and Z1–, all have
the same Ksp value. Which salt has the highest molar solubility?
A) AV
B) B2W
C) C2X3
D) DY2
E) EZ3
41. Ksp for PbF2 is 4.0 ×10-8. If a 0.034 M NaF solution is saturated with PbF2, what is
[Pb2+] in solution?
A) 1.2 × 10-6 M
B) 4.6 × 10-11 M
C) 1.0 × 10-3 M
D) 3.5 × 10-5 M
E) 1.4 × 10-9 M
42. Which of Figures I–IV represent(s) the result of mixing aqueous solutions of Na2S and
NiCl2 in which the ion product Qc > Ksp for the insoluble product? (C = cation, A =
anion)
=A
=C
I
A)
B)
C)
D)
E)
II
III
only I
only II
only III
only IV
both I and II
Page 10
IV
43. Suppose 50.00 mL of 2.0 × 10–5 M Fe(NO3)3 is added to 50.00 mL of 2.0 ×10–5 M KIO3.
Which of the following statements is true? For Fe(IO3)3, Ksp = 1.0 × 10–14.
A) A precipitate forms because Qc > Ksp.
B) A precipitate forms because Qc < Ksp.
C) No precipitate forms because Qc > Ksp.
D) No precipitate forms because Qc < Ksp.
E) Nothing happens.
44. What is the minimum concentration of Cd2+ required to begin precipitating Cd(OH)2(s)
in a solution of pH 10.19? For Cd(OH)2, Ksp = 5.3 10–15.
A) 8.2 10–5 M
B) 2.2 10–7 M
C) 3.4 10–11 M
D) 5.1 10–17 M
E) 7.7  10–5 M
45. If 200 mL of 1 10–7 M AgNO3 is mixed with 200 mL of 1
occur? For AgI, Ksp = 8.3 10–17.
A) Silver(I) iodide will precipitate.
B) No precipitate will form.
C) Sodium nitrate will precipitate.
D) Silver(I) nitrate will precipitate.
E) Sodium iodide will precipitate.
46. If 400 mL of 1 10–4 M Ca(NO3)2 is mixed with 400 mL of 1
occur? For CaF2, Ksp = 3.4 10–11.
A) Calcium fluoride will precipitate.
B) No precipitate will form.
C) Sodium nitrate will precipitate.
D) Calcium nitrate will precipitate.
E) Sodium fluoride will precipitate.
10–8 M NaI, what will
10–4 M NaF, what will
47. Sodium chloride is added slowly to a solution that is 0.010 M in Cu+, Ag+, and Au+. The
Ksp values for the chloride salts are 1.9 × 10–7, 1.6 × 10–10, and 2.0 × 10–13, respectively.
Which compound will precipitate first?
A) CuCl(s)
B) AgCl(s)
C) AuCl(s)
D) All will precipitate at the same time.
E) It cannot be determined.
Page 11
48. Which of the following substances will increase the molar solubility of nickel(II)
phosphate in a saturated solution?
A) Na3PO4
B) HNO3
C) NH4Cl
D) (NH4)3PO4
E) KOH
49. Which of the following insoluble salts will dissolve upon reaction with excess
ammonia?
A) PbSO4
B) BaSO4
C) CaCO3
D) HgS
E) AgCl
50. What is the concentration of Cd2+ in a 0.010 M Cd(NO3)2 solution that is also 1.0 M
NH3? For Cd(NH3)42+, Kf = 1.0 107.
A) 3.2 10–4 M
B) 1.2 10–9 M
C) 3.2 10–5 M
D) 1.0 10–9 M
E) 1.0  10–2 M
Page 12
Answer Key
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
B
D
A
A
B
E
C
C
D
B
D
A
E
A
B
B
B
E
C
D
A
D
D
D
C
B
C
C
A
C
C
B
D
A
C
D
C
D
B
C
D
C
D
B
Page 13
45.
46.
47.
48.
49.
50.
A
B
C
B
E
B
Page 14