Chemistry, 6e (McMurry/Fay)
Chapter 15 Applications of Aqueous Equilibria
15.1 Multiple-Choice Questions
1) Which is a net ionic equation for the neutralization of a strong acid with a strong base?
A) HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
B) H3O+(aq) + OH–(aq) ⇌ 2 H2O(l)
C) HF(aq) + NaOH(aq) ⇌ H2O(l) + NaF(aq)
D) HF(aq) + OH–(aq) ⇌ H2O(l) + F–(aq)
2) Which is a net ionic equation for the neutralization of a weak acid with a strong base?
A) HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
B) H3O+(aq) + OH–(aq) ⇌ 2 H2O(l)
C) HF(aq) + NaOH(aq) ⇌ H2O(l) + NaF(aq)
D) HF(aq) + OH–(aq) ⇌ H2O(l) + F–(aq)
3) Which is a net ionic equation for the neutralization reaction of a strong acid with a weak base?
A) HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
B) H3O+(aq) + OH–(aq) ⇌ 2 H2O(l)
C) HCl(aq) + NH3(aq) ⇌ NH4Cl(aq)
D) H3O+(aq) + NH3(aq) ⇌ NH4+(aq) + H2O(l)
4) Which is a net ionic equation for the neutralization reaction of a weak acid with a weak base?
A) H3O+(aq) + OH–(aq) ⇌ 2 H2O(l)
B) HF(aq) + NH3(aq) ⇌ NH4+(aq) + F–(aq)
C) HF(aq) + OH–(aq) ⇌ H2O(l) + F–(aq)
D) H3O+(aq) + NH3(aq) ⇌ NH4+(aq) + H2O(l)
2
5) What is the equation relating the equilibrium constant Kn for the neutralization of a weak acid with a
weak base to the Ka of the acid, the Kb of the base and Kw?
A) Kn = KaKbKw
B) Kn =
ab
w
KK
K
C) Kn =
aw
b
KK
K
D) Kn =
bw
a
KK
K
6) What is the approximate value of the equilibrium constant, Kn, for the neutralization of acetic acid
with sodium hydroxide, shown in the equation below? The Ka for acetic acid is 1.8 × 10–5.
CH3CO2H(aq) + NaOH(aq) ⇌ H2O(l) + NaCH3CO2(aq)
A) 1.8 × 10-19
B) 5.6 × 10-10
C) 1.8 × 10-8
D) 1.8 × 109
7) What is the approximate value of the equilibrium constant, Kn, for the neutralization of pyridine with
hydrochloric acid, shown in the equation below? The Kb for pyridine is 1.8 × 10–9.
HCl(aq) + C5H5N(aq) ⇌ C5H5NHCl(aq)
A) 5.6 × 10-10
B) 5.6 × 10-6
C) 1.8 × 105
D) 5.6 × 108
8) What is the approximate value of the equilibrium constant, Kn, for the neutralization of nitrous acid
with ammonia, shown in the equation below? The Ka for HNO2 is 4.5 × 10–4 and the Kb for NH3 is
1.8 × 10–5.
HNO2(aq) + NH3(aq) ⇌ NH4NO2(aq)
A) 8.1 × 105
B) 1.8 × 109
C) 4.5 × 1010
D) 8.1 × 1019
9) What is the approximate value of the equilibrium constant, Kn, for the neutralization of hydrochloric
acid with sodium hydroxide, shown in the equation below?
HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
A) 1.0 × 102
B) 1.0 × 107
C) 1.0 × 1014
D) 1.0 × 1028
10) The neutralization constant Kn for the neutralization of acetylsalicylic acid (C9H8O4) and codeine
(C18H21NO3) is 4.8 × 104. The acid dissociation constant Ka for acetylsalicylic acid is 3.0 × 10-4.
What is the base dissociation constant Kb for codeine?
A) 4.8 × 10-24
B) 6.3 × 10-23
C) 1.6 × 10-6
D) 1.4 × 1015
11) The neutralization constant Kn for the neutralization of phenobarbital (C12H12N2O3) and morphine
(C17H19NO3) is 2.9. The acid dissociation constant Ka for phenobarbital is 3.9 × 10-8. What is the
base dissociation constant Kb for morphine?
A) 1.3 × 10-22
B) 6.3 × 10-23
C) 7.4 × 10-7
D) 1.1 × 107
12) Which of these neutralization reactions has a pH = 7 when equal molar amounts of acid and base are
mixed?
A) CH3CO2H(aq) + NaOH(aq) ⇌ H2O(l) + NaCH3CO2(aq)
B) HCl(aq) + C5H5N(aq) ⇌ C5H5NHCl(aq)
C) HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
D) HNO2(aq) + NH3(aq) ⇌ NH4NO2(aq)
13) Which of these neutralization reactions has a pH < 7 when equal molar amounts of acid and base are
mixed?
A) CH3CO2H(aq) + NaOH(aq) ⇌ H2O(l) + NaCH3CO2(aq)
B) HCl(aq) + C5H5N(aq) ⇌ C5H5NHCl(aq)
C) HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
D) H2SO4(aq) + 2 KOH(aq) ⇌2 H2O(l) + K2SO4(aq)
14) Which of these neutralization reactions has a pH > 7 when equal moles of acid and base are mixed?
A) CH3CO2H(aq) + NaOH(aq) ⇌ H2O(l) + NaCH3CO2(aq)
B) HCl(aq) + C5H5N(aq) ⇌ C5H5NHCl(aq)
C) HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq)
D) H2SO4(aq) + 2 KOH(aq) ⇌2 H2O(l) + K2SO4(aq)
15) What is the common ion in a solution prepared by mixing 0.10 M NaCH3CO2 with 0.10 M
CH3CO2H?
A) H3O+
B) Na+
C) CH3CO2–
D) OH–
16) When 50 mL of 0.10 M NH4Cl is added to 50 mL of 0.10 M NH3, relative to the pH of the 0.10 M
NH3 solution the pH of the resulting solution will
A) become 7.
B) decrease.
C) increase.
D) remain the same.
17) When 50 mL of 0.10 M NaF is added to 50 mL of 0.10 M HF, relative to the pH of the 0.10 M HF
solution the pH of the resulting solution will
A) become 7.
B) decrease.
C) increase.
D) remain the same.
18) What is the hydronium ion concentration in a solution prepared by mixing 50.00 mL of 0.10 M HCN
with 50.00 mL of NaCN? Assume that the volumes of the solutions are additive and that Ka =
4.9 × 10-10 for HCN.
A) 2.4 × 10-10 M
B) 4.9 × 10-10 M
C) 9.8 × 10-10 M
D) 7.0 × 10-6 M
19) What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M CH3CO2H with 25.00 mL of
0.050 M CH3CO2Na? Assume that the volume of the solutions are additive and that Ka = 1.8 × 10-5 for
CH3CO2H.
A) 2.87
B) 4.44
C) 4.74
D) 5.05
20) What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M NH3 with 25.00 mL of 0.10 M
NH4Cl? Assume that the volume of the solutions are additive and that Kb = 1.8 × 10-5 for NH3.
A) 8.95
B) 9.26
C) 9.56
D) 11.13
21) What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M methylamine, CH3NH2, with
25.00 mL of 0.10 M methylammonium chloride, CH3NH3Cl? Assume that the volume of the solutions
are additive and that Kb = 3.70 × 10-4 for methylamine.
A) 10.27
B) 10.57
C) 10.87
D) 11.78
22) When equal molar amounts of the following sets of compounds are mixed in water, which will not
form a buffer solution?
A) NaH2PO4 with Na2HPO4
B) NH3 with NH4Cl
C) CH3CO2H with NaCH3CO2
D) HNO3 with NaNO3
23) Which of the following combinations of chemicals could be used to make a buffer solution?
A) HCl/NaOH
B) HCl/NH3
C) HCl/H3PO4
D) NaOH/NH3
24) Which statement about buffers is true?
A) Buffers have a pH = 7.
B) Buffers consist of a strong acid and its conjugate base.
C) A buffer does not change pH on addition of a strong acid or strong base.
D) Buffers resist change in pH upon addition of small amounts of strong acid or strong base.
25) What is the pH of a buffered system made by dissolving 17.42 g of KH2PO4 and 20.41 g of
K2HPO4 in water to give a volume of 200.0 mL? The Ka2 for dihydrogen phosphate is 6.2 × 10-8 and
the equilibrium reaction of interest is
H2PO4–(aq) + H2O(l) ⇌ H3O+(aq) + HPO4–(aq).
A) 7.03
B) 7.17
C) 7.38
D) 7.58
26) What is the pH of a buffer system made by dissolving 10.70 grams of NH4Cl and 20.00 mL of 12.0
M NH3 in enough water to make 1.000 L of solution? Kb = 1.8 × 10-5 for NH3.
A) 9.18
B) 9.26
C) 9.34
D) 11.03
27) TRIS {(HOCH2)3CNH2} is one of the most common buffers used in biochemistry. A solution is
prepared by adding enough TRIS and 12 M HCl(aq) to give 1.00 L of solution with [TRIS] = 0.30 M
and [TRISH+] = 0.60 M. What is the pH of this buffered system if the pKb is 5.92?
A) 5.92
B) 6.22
C) 7.78
D) 8.08
28) A buffer solution is prepared by dissolving 0.200 mol of NaH2PO4 and 0.100 mol of NaOH in
enough water to make 1.00 L of solution. What is the pH of the H2PO4–/HPO42- buffer if the
Ka2 = 6.2 × 10-8?
A) 6.91
B) 7.21
C) 7.51
D) 7.71
29) What is the pH of 1 L of 0.30 M TRIS, 0.60 M TRISH+ buffer to which one has added 5.0 mL of 12
M HCl? The Kb for the TRIS/TRISH+ is 1.2 × 10-6.
A) 5.92
B) 6.36
C) 7.36
D) 7.64
30) A buffer solution is prepared by dissolving 27.22 g of KH2PO4 and 3.37 g of KOH in enough water
to make 0.100 L of solution. What is the pH of the H2PO4–/HPO42- buffer if the Ka2 = 6.2 × 10-8?
A) 6.84
B) 7.00
C) 7.21
D) 7.84
31) What is the [CH3CO2–]/[CH3CO2H] ratio necessary to make a buffer solution with a pH of 4.44?
Ka = 1.8 × 10-5 for CH3CO2H.
A) 0.50:1
B) 0.94:1
C) 1.1:1
D) 2.0:1
32) What is the pH of a buffer solution made by mixing 50.0 mL of 0.100 M potassium hydrogen
phthalate with 13.6 mL of 0.100 M NaOH and diluting the mixture to 100.0 mL with water? The Ka2 for
hydrogen phthalate is 3.1 × 10-6.
A) 3.25
B) 5.08
C) 5.51
D) 5.94
33) What volume of 0.100 M NaOH is needed to make 100.0 mL of a buffer solution with a pH of 6.00
if one starts with 50.0 mL of 0.100 M potassium hydrogen phthalate? The Ka2 for potassium hydrogen
phthalate is 3.1 × 10-6.
A) 22.4 mL
B) 27.6 mL
C) 30.2 mL
D) 37.8 mL
34) What is the magnitude of the change in pH when 0.005 moles of HCl is added to 0.100 L of a buffer
solution that is 0.100 M in CH3CO2H and 0.100 M NaCH3CO2? The Ka for acetic acid is1.8 × 10-5.
A) 0.00
B) 0.20
C) 0.47
D) 1.30
35) What is the resulting pH when 0.005 moles of KOH is added to 0.100 L of a buffer solution that is
0.100 M in H2PO4– and 0.100 M HPO42- and the Ka2 = 6.2 × 10-8?
A) 5.21
B) 5.61
C) 6.73
D) 7.69
36) What is the Henderson-Hasselbalch equation for the acidic buffer HA/A–?
A) pH = -log[H3O+]
B) pH = 14 – pOH
C) pH = pKa + log{[A–]/[HA]}
D) pH = pKa – log{[A–]/[HA]}
37) What is not a correct expression for the weak acid HA?
A) Ka = [H3O+][A–]/[HA]
B) pKa = pH – log{[A–]/[HA]}
C) pKa = logKa
D) pKa = 14 – pKb
38) Which is the best acid to use in the preparation of a buffer with pH = 3.3?
A) HOI (Ka = 2.0 × 10–11)
B) HNO2 (Ka = 4.5 × 10–4)
C) HNO3
D) HIO3 ((Ka = 1.7 × 10–1)
39) Which is the best acid to use in the preparation of a buffer with pH = 9.3?
A) CH3NH2 (Kb = 3.7 × 10–4)
B) NH3 (Kb = 1.8 × 10–5)
C) NH2OH (Kb = 9.1 × 10–9)
D) C6H5NH2 (Kb = 4.3 × 10–10)
40) What is the percent dissociation of glycine if the solution has a pH = 8.60 and a pKa = 9.60?
A) 50%
B) 9%
C) 5%
D) 1%
41) What is the percent dissociation of acetic acid if the solution has a pH = 4.74 and a pKa = 4.74?
A) 100%
B) 50%
C) 10%
D) 1%
42) What is the percent dissociation of ascorbic acid if the solution has a pH = 5.50 and a pKa = 4.10?
A) 96%
B) 10%
C) 5%
D) 1%
43) At what pH is the amino acid glycine with a Ka of 2.51 × 10-10 sixty-six (66%) percent dissociated?
A) 9.60
B) 9.89
C) 10.10
D) 10.60
44) What volume of 5.00 × 10–3 M HNO3 is needed to titrate 100.00 mL of 5.00 × 10–3 M Ca(OH)2 to
the equivalence point?
A) 12.5 mL
B) 50.0 mL
C) 100. mL
D) 200. mL
45) What is the pH of a solution made by mixing 30.00 mL of 0.10 M HCl with 40.00 mL of 0.10 M
KOH? Assume that the volumes of the solutions are additive.
A) 0.85
B) 1.85
C) 12.15
D) 13.15
46) Which of the following titrations result in a basic solution at the equivalence point?
A) HI titrated with NaCH3CO2
B) HOCl titrated with NaOH
C) HBr titrated with KOH
D) Pb(NO3)2 titrated with NaI
47) What is the pH at the equivalence point of a weak acid-strong base titration?
A) pH < 7
B) pH = 7
C) pH > 7
D) pH = 14.00
48) What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of
aqueous formic acid requires 29.80 mL of 0.0567 M NaOH? Ka = 1.8 × 10-4 for formic acid.
A) 2.46
B) 5.88
C) 8.12
D) 11.54
49) What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of
aqueous hydrofluoric acid requires 30.00 mL of 0.400 M NaOH? Ka = 6.76 × 10-4 for HF.
A) 1.74
B) 5.75
C) 8.25
D) 12.26
50) The equivalence point pH of the titration of four weak acids is given. Which is the strongest acid?
A) 7.24
B) 7.86
C) 8.12
D) 8.43
51) Formic acid (HCO2H, Ka = 1.8 × 10-4) is the principal component in the venom of stinging ants.
What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL
of 0.0567 M NaOH to reach the equivalence point?
A) 0.0134 M
B) 0.0476 M
C) 0.0567 M
D) 0.0676 M
52) What is the pH of the resulting solution if 30.00 mL of 0.10 M acetic acid is added to 10.00 mL of
0.10 M NaOH? Assume that the volumes of the solutions are additive. Ka = 1.8 × 10-5 for CH3CO2H.
A) 9.56
B) 8.95
C) 5.05
D) 4.44
53) What is the pH of a solution made by mixing 30.00 mL of 0.10 M acetic acid with 30.00 mL of
0.10 M KOH? Assume that the volumes of the solutions are additive. Ka = 1.8 × 10-5 for CH3CO2H.
A) 5.28
B) 7.00
C) 8.72
D) 10.02
54) What is the pH of a solution made by mixing 30.00 mL of 0.10 M acetic acid with 40.00 mL of
0.10 M KOH? Assume that the volumes of the solutions are additive. Ka = 1.8 × 10-5 for CH3CO2H.
A) 8.26
B) 9.26
C) 11.13
D) 12.15
55) Which of the following titrations result in an acidic solution at the equivalence point?
A) CH3COOH titrated with NaOH
B) KF titrated with KOH
C) HCl titrated with NaOH
D) C5H5N titrated with HCl
56) Sodium hypochlorite, NaOCl, is the active ingredient in household bleach. What is the concentration
of hypochlorite ion if 20.00 mL of bleach requires 28.30 mL of 0.500 M HCl to reach the equivalence
point?
A) 0.208 M
B) 0.353 M
C) 0.708 M
D) 1.21 M
57) What is the pH at the equivalence point of a weak base-strong acid titration if 20.00 mL of NaOCl
requires 28.30 mL of 0.50 M HCl? Ka = 3.0 × 10-8 for HOCl.
A) 0.30
B) 3.18
C) 3.76
D) 4.03
58) The equivalence point pH of the titration of four weak bases is given. Which is the strongest base?
A) 4.21
B) 5.67
C) 6.33
D) 7.58
59) What is the pH of the resulting solution if 25 mL of 0.432 M methylamine, CH3NH2, is added to
15 mL of 0.234 M HCl? Assume that the volumes of the solutions are additive. Ka = 2.70 × 10-11 for
CH3NH3+.
A) 3.11
B) 3.74
C) 10.26
D) 10.89
60) Sulfurous acid, H2SO3 has acid dissociation constants Ka1 = 1.5 × 10–2 and Ka2 = 6.3 × 10–8.
What is the pH after 10.00 mL of 0.1000 M NaOH is added to 10.00 mL of 0.1000 M H2SO3?
A) 1.82
B) 3.60
C) 4.25
D) 7.20
61) Oxalic acid, H2C2O4 has acid dissociation constants Ka1 = 5.9 × 10–2 and Ka2 = 6.4 × 10–5.
What is the pH after 20.00 mL of 0.0500 M NaOH is added to 5.00 mL of 0.2000 M H2C2O4?
A) 1.23
B) 2.10
C) 2.80
D) 4.19
62) The dissociation equilibrium constants for the protonated form of alanine (a diprotic amino acid,
H2X+) are Ka1 = 4.6 × 10-3 and Ka2 = 2.0 × 10–10. What is the pH of 50.00 mL of a 0.0500 M solution
of alanine after 25.00 mL of 0.100 M NaOH has been added?
A) 2.34
B) 4.85
C) 5.59
D) 6.72
63) The dissociation equilibrium constants for the protonated form of alanine (a diprotic amino acid,
H2X+) are Ka1 = 4.6 × 10-3 and Ka2 = 2.0 × 10–10. What is the pH of 50.00 mL of a 0.050 M solution
of alanine after 37.50 mL of 0.100 M NaOH has been added?
A) 4.85
B) 6.02
C) 7.39
D) 9.70
64) The dissociation equilibrium constants for the protonated form of alanine (a diprotic amino acid
H2X+) are Ka1 = 4.6 × 10-3 and Ka2 = 2.0 × 10–10. What is the pH of 50.00 mL of a 0.100 M solution
of alanine after 100.00 mL of 0.100 M NaOH has been added?
A) 9.70
B) 10.69
C) 11.11
D) 12.70
65) The balanced equation for the solubility equilibrium of Fe(OH)2 is shown below. What is the
equilibrium constant expression for the Ksp of Fe(OH)2?
Fe(OH)2(s) ⇌ Fe2+(aq) + 2 OH–(aq)
A) Ksp = {[Fe2+][OH–]2}/{[Fe(OH)2][H2O]}
B) Ksp = {[Fe2+][OH–]2}/[Fe(OH)2]
C) Ksp = [Fe2+][OH–]2
D) Ksp = 1/{[Fe2+][OH–]2}
66) What is the equilibrium constant expression for the Ksp of Ca3(PO4)2?
A) Ksp = [Ca2+]3[PO43-]2
B) Ksp = {[Ca2+]3[PO43-]2}/[Ca3PO4]
C) Ksp = {[Ca2+]3[PO43-]2}/{[Ca3PO4][H2O]}
D) Ksp = 1/{[Ca2+]3[PO43-]2}
67) What is the silver ion concentration for a saturated solution of Ag2CO3 if the Ksp for Ag2CO3 is
8.4 × 10-12?
A) 2.90 × 10-6 M
B) 2.03 × 10-4 M
C) 2.56 × 10-4 M
D) 4.06 × 10-4 M
68) What is the chromium ion concentration for a saturated solution of Cr(OH)3 if the Ksp for Cr(OH)3
is 6.7 × 10-31?
A) 8.19 × 10-16 M
B) 1.26 × 10-8 M
C) 2.17 × 10-8 M
D) 3.76 × 10-8 M
69) What is the most soluble salt of the following set?
A) Ba(OH)2 with Ksp = 5.0 × 10-3
B) Ca(OH)2 with Ksp = 4.7 × 10-6
C) Cd(OH)2 with Ksp = 5.3 × 10-15
D) Fe(OH)2 with Ksp = 2.5 × 10-37
70) What is the most soluble salt of the following set?
A) AgCN with Ksp = 6.0 × 10-17
B) Al(OH)3 with Ksp = 1.9 × 10-33
C) Fe(OH)3 with Ksp = 2.6 × 10-39
D) Sn(OH)2 with Ksp = 1.6 × 10-19
71) Calculate the Ksp for silver sulfate if the solubility of Ag2SO4 in pure water is 4.5 g/L.
A) 3.0 × 10-6
B) 1.2 × 10-5
C) 2.1 × 10-4
D) 4.2 × 10-4
72) Calculate the solubility (in g/L) of silver carbonate in water at 25°C if the Ksp for Ag2CO3 is
8.4 × 10-12.
A) 8.0 × 10-4 g/L
B) 3.5 × 10-2 g/L
C) 4.4 × 10-2 g/L
D) 5.6 × 10-2 g/L
73) What is the molar solubility of CaF2 in 0.10 M NaF solution at 25°C? The Ksp for CaF2 is
A) 8.5 × 10-10 M
B) 3.4 × 10-10 M
C) 3.4 × 10-9 M
D) 2.0 × 10-4 M
74) What is the molar solubility of Mg(OH)2 in a basic solution with a pH of 12.00? Ksp for Mg(OH)2
is 5.6 × 10-12.
A) 5.6 × 10-10 M
B) 5.6 × 10-8 M
C) 2.4 × 10-6 M
D) 1.1 × 10-4 M
75) Calculate the molar solubility of thallium(I) chloride in 0.30 M NaCl at 25°C. Ksp for TlCl is
1.7 × 10-4.
A) 5.1 × 10-5 M
B) 5.7 × 10-4 M
C) 7.1 × 10-3 M
D) 1.3 × 10-2 M
76) What is the molar solubility of lead(II) chromate in 0.10 M HNO3 if the Ksp for PbCrO4 is
2.8 × 10-13? and the Ka2 for H2CrO4 is 3.0 × 10-7? Note that H2CrO4 is considered to be a strong acid.
A) 9.2 × 10-11 M
B) 2.9 × 10-10 M
C) 9.3 × 10-7 M
D) 3.1 × 10-4 M
77) In which of the following solutions would solid PbCl2 be expected to be the least soluble at 25°C?
A) 0.1 M HCl
B) 0.1 M NaCl
C) 0.1 M CaCl2
D) 0.1 M KNO3
78) What is the molar solubility of AgCl in 0.10 M NH3? Ksp for AgCl is 1.8 × 10-10 and the Kf for
Ag(NH3)2+ is 1.7 × 107.
A) 1.3 × 10-5 M
B) 5.0 × 10-3 M
C) 5.5 × 10-3 M
D) 5.5 × 10-2 M
79) What is the molar solubility of AgCl in 1.0 M K2S2O3 if the complex ion Ag(S2O3)23- forms? The
Ksp for AgCl is 1.8 × 10-10 and the Kf for Ag(S2O3)23- is 2.9 × 1013.
A) 0.50 M
B) 1.0 M
C) 1.5 M
D) 2.0 M
80) What is the molar solubility of AgCl in 0.10 M NaCN if the colorless complex ion Ag(CN)2– forms?
Ksp for AgCl is 1.8 × 10-10 and Kf for Ag(CN)2– is
A) 0.050 M
B) 0.10 M
C) 0.20 M
D) 0.40 M
18
81) Which of the following metal hydroxides are amphoteric?
A) Al(OH)3, Zn(OH)2, Cr(OH)3, Sn(OH)2
B) Cu(OH)2, Mn(OH)2, Fe(OH)2, Fe(OH)3
C) Be(OH)2, Ca(OH)2, Ba(OH)2, Sr(OH)3
D) LiOH, NaOH, KOH, RbOH
82) Which of the following reactions are not consistent with the concept of acid base amphoterism?
A) Al(OH)3(s) + OH–(aq) → Al(OH)4–(aq)
B) Al(OH)3(s) + 3 H3O+(aq) → Al3+(aq) + 6 H2O(l)
C) H2O(l) + H2O(l) ⇌ H3O+(aq) + OH–(aq)
D) Al(OH)3(s) ⇌ Al3+(aq) + 3 OH–(aq)
83) Precipitation of an ionic compound will occur upon mixing of desired reagents if the initial ion
product is ________.
A) greater than the Ksp
B) equal to the pKsp
C) equal to the Ksp
D) less than the Ksp
84) Potassium chromate is slowly added to a solution containing 0.20 M AgNO3 and 0.20 M Ba(NO3)2.
Describe what happens if the Ksp for Ag2CrO4 is 1.1 × 10-12 and the Ksp of BaCrO4 is 1.2 × 10-10.
A) The BaCrO4 precipitates first out of solution.
B) The Ag2CrO4 precipitates first out of solution and then BaCrO4 precipitates.
C) Both BaCrO4 and Ag2CrO4 precipitate simultaneously out of solution.
D) Neither BaCrO4 nor Ag2CrO4 precipitates out of solution.
85) 0.10 M potassium chromate is slowly added to a solution containing 0.20 M AgNO3 and 0.20 M
Ba(NO3)2. What is the Ag+ concentration when BaCrO4 just starts to precipitate? Ksp for Ag2CrO4
and BaCrO4 are 1.1 × 10-12 and 1.2 × 10-10, respectively.
A) 6.5 × 10-5 M
B) 1.3 × 10-4 M
C) 3.2 × 10-4 M
D) 4.3 × 10-2 M
86) Which metal sulfides can be precipitated from a solution that is 0.01 M in Mn2+, Zn2+, Pb2+ and
Cu2+ and 0.10 M in H2S at a pH of 1.0?
A) MnS
B) CuS
C) PbS, CuS
D) ZnS, PbS, CuS
87) Which metal sulfides can be precipitated from a solution that is 0.01 M in Mn2+, Zn2+, Pb2+ and
Cu2+ and 0.10 M in H2S at a pH of 0.50?
A) MnS
B) CuS
C) PbS, CuS
D) ZnS, PbS, CuS
88) Which metal ions can be precipitated out of solution as chlorides?
A) Ag+, Hg2+, Co2+
B) Cu2+, Cd2+, Bi3+
C) Ag+, Hg22+, Pb2+
D) Na+, K+, Mg2+
89) A solution may contain the following ions Ag+, Cu2+, Cd2+, Mn2+, Ni2+ and Na+. A white
precipitate formed when 0.10 M NaCl was added and after this was removed the solution was treated
with H2S gas under acidic conditions and no precipitate formed. When the solution was made basic and
again treated with H2S gas a dark colored precipitate formed. If no further tests were made then what
conclusions can you draw?
A) possible ions present Ag+, Mn2+, Ni2+
B) possible ions present Ag+, Mn2+, Ni2+, Na+
C) possible ions present Ag+, Cu2+, Cd2+
D) possible ions present Ag+, Cu2+, Cd2+, Na+
90) A solution may contain the following ions Ag+, Cu2+, Mn2+, Ca2+, and Na+. No precipitate
formed when 0.10 M NaCl was added but a dark colored precipitate formed when H2S was added to an
acidic portion of the solution. After the removal of the solid the solution was made basic and more H2S
was added and a dark precipitate again formed. Treatment of the filtrate with (NH4)2CO3 resulted in a
white precipitate. If no further tests were made then what conclusions can you draw?
A) possible ions present Cu2+, Mn2+, Na+
B) possible ions present Cu2+, Mn2+, Ca2+
C) possible ions present Cu2+, Mn2+, Ca2+, Na+
D) possible ions present Ag+, Cu2+, Mn2+, Ca2+, Na+
91) Which set of ions precipitate as sulfides?
A) Ag+, Pb2+, Mn2+
B) Pb2+, Fe2+, Ca2+
C) Co2+, Ba2+, K+
D) NH4+, Na+, K+
92) Which pair of ions can be separated by the addition of chloride ion?
A) Ag+ and Co2+
B) Cu2+ and Bi3+
C) Pb2+ and Hg22+
D) Ca2+ and Ba2+