The following plot shows a titration curve for the titration of 1.00 L of 1.00 M diprotic acid H2A
with NaOH.
125) A buffer region is indicated by which point(s) a-d?
A) point a
B) points a and c
C) point b
D) points b and d
126) Which point a-d represents the HX–/X2– buffer region?
A) point a
B) point b
C) point c
D) point d
127) Which point a-d represents the H2X/HX– buffer region?
A) point a
B) point b
C) point c
D) point d
128) Which point a-d represents the first equivalence point?
A) point a
B) point b
C) point c
D) point d
129) Which point a-d represents the second equivalence point?
A) point a
B) point b
C) point c
D) point d
130) Which point a-d represents pKa1?
A) point a
B) point b
C) point c
D) point d
131) Which point a-d represents pKa2?
A) point a
B) point b
C) point c
D) point d
132) What is the pH at the first equivalence point?
A) pH = pKa1
B) pH = 14 – pKa1
C) pH = (pKa1 + pKa2)/2
D) pH = pKa1 + pKa2
133) The following plot shows a titration curve for the titration of 1.00 L of 1.00 M diprotic acid
H2A+ with NaOH. Which point a-d represents the isoelectric point?
A) point a
B) point b
C) point c
D) point d
The following pictures represent solutions of CuS, which may also contain ions other than Cu2+
and S2- which are not shown. Gray spheres represent Cu2+ ions and dotted spheres represent S2-
ions.
134) If solution (1) is a saturated solution of CuS, which of solutions (2)-(4) are unsaturated?
A) only (2)
B) only (3)
C) only (4)
D) (3) and (4)
135) If solution (1) is a saturated solution of CuS, which of solutions (2)-(4) are saturated?
A) (2)
B) (3)
C) (4)
D) none of the above
136) If solution (1) is a saturated solution of CuS, which of solutions (2)-(4) are supersaturated?
A) (2)
B) (3)
C) (4)
D) none of the above
The following pictures represent solutions of AgCl, which may also contain ions other than Ag+
and Cl– which are not shown. Gray spheres represent Ag+ ions and dotted spheres represent Cl–
ions.
137) If solution (1) is a saturated solution of AgCl, which of solutions (1)-(4) represents the
solution after a small amount of HCl is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
138) If solution (1) is a saturated solution of AgCl, which of solutions (1)-(4) represents the
solution after a small amount of HNO3 is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
139) If solution (1) is a saturated solution of AgCl, which of solutions (1)-(4) represents the
solution after a small amount of AgNO3 is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
140) If solution (1) is a saturated solution of AgCl, which of solutions (1)-(4) represents the
solution after a small amount of NH3 is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
The following pictures represent solutions of CaCO3, which may also contain ions other than
Ca2+ and CO32- which are not shown. Gray spheres represent Ca2+ ions and unshaded spheres
represent CO32- ions.
141) If solution (1) is a saturated solution of CaCO3, which of solutions (1)-(4) represents the
solution after a small amount of NaOH is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
142) If solution (1) is a saturated solution of CaCO3, which of solutions (1)-(4) represents the
solution after a small amount of HNO3 is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
143) If solution (1) is a saturated solution of CaCO3, which of solutions (1)-(4) represents the
solution after a small amount of Ca(NO3)2 is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
144) If solution (1) is a saturated solution of CaCO3, which of solutions (1)-(4) represents the
solution after a small amount of K2CO3 is added and equilibrium is restored?
A) (1)
B) (2)
C) (3)
D) (4)
15.2 Algorithmic Questions
1) 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 =
A) 1.5 × 10-10 M
B) 4.9 × 10-10 M
C) 1.6 × 10-9 M
D) 7.0 × 10-6 M
2) What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M CH3CO2H with 25.00
mL of 0.010 M CH3CO2Na? Assume that the volume of the solutions are additive and that Ka =
1.8 × 10-5 for CH3CO2H.
A) 2.87
B) 3.74
C) 4.75
D) 5.74
3) What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M NH3 with 5.00 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) 8.25
B) 10.26
C) 10.25
D) 11.13
4) What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M methylamine, CH3NH2,
with 20.00 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) 10.17
B) 10.57
C) 10.97
D) 11.78
5) What is the pH of a buffer system prepared by dissolving 10.70 grams of NH4Cl and 40.00
mL of 12 M NH3 in enough water to make 1.000 L of solution? Kb = 1.80 × 10-5 for NH3.
A) 8.88
B) 9.26
C) 9.64
D) 11.32
6) What is the [CH3CO2-]/[CH3CO2H] ratio necessary to make a buffer solution with a pH of
4.34? Ka = 1.8 × 10-5 for CH3CO2H.
A) 0.39:1
B) 0.91:1
C) 1.09:1
D) 2.5:1
7) What is the pH of a one liter solution that is 0.100 M in N and 0.100 M in N Cl after 1.2
g of NaOH has been added? for N is 1.8 × .
A) 9.52
B) 9.26
C) 9.62
D) 11.12
8) What volume of 5.00 × 10–3 M HNO3 is needed to titrate 80.00 mL of 5.00 × 10–3 M
Ca(OH)2 to the equivalence point?
A) 10.0 mL
B) 40.0 mL
C) 80.0 mL
D) 160. mL
9) What is the pH of a solution made by mixing 25.00 mL of 0.100 M HCl with 40.00 mL of
0.100 M KOH? Assume that the volumes of the solutions are additive.
A) 0.64
B) 1.64
C) 12.36
D) 13.36
10) 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 0.3567 M NaOH? Ka =1.8 × 10-4 for
formic acid.
A) 2.06
B) 5.48
C) 8.52
D) 11.94
11) 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
12) 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
13) What is the pH of the resulting solution if 25.00 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) 9.43
B) 9.08
C) 4.92
D) 4.57
14) What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL
of 0.10 M KOH? Assume that the volumes of the solutions are additive. Ka = for
CH3CO2H.
A) 5.28
B) 7.00
C) 8.72
D) 10.02
15) What is the pH of a solution made by mixing 30.00 mL of 0.10 M acetic acid with 50.00 mL
of 0.100 M KOH? Assume that the volumes of the solutions are additive. Ka = 1.8 × 10-5 for
A) 8.26
B) 9.26
C) 11.13
D) 12.40
16) Sodium hypochlorite, NaOCl, is the active ingredient in household bleach. What is the
concentration of hypochlorite ion if 20.00 mL of bleach requires 32.00 mL of 0.500 M HCl to
reach the equivalence point?
A) 0.300 M
B) 0.312 M
C) 0.800 M
D) 1.30 M
17) 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
18) What is the pH of the resulting solution if 45 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) 2.77
B) 4.09
C) 9.91
D) 11.23
19) Calculate the Ksp for silver sulfite if the solubility of Ag2SO3 in pure water is 4.6 × 10-3
g/L.
A) 3.8 × 10-15
B) 1.5 × 10-14
C) 2.4 × 10-10
D) 4.8 × 10-10
20) Calculate the solubility (in g/L) of silver chromate in water at 25°C if the Ksp for Ag2CrO4
is 1.1 × .
A) 3.5 × 10-4 g/L
B) 6.5 × 10-5 g/L
C) 2.7 × 10-2 g/L
D) 3.4 × 10-2 g/L
21) What is the molar solubility of Mg(OH)2 in a basic solution with a pH of 12.50? Ksp for
Mg(OH)2 is
A) 1.8 × 10-10 M
B) 5.6 × 10-9 M
C) 2.4 × 10-6 M
D) 1.1 × 10-4 M
22) Calculate the molar solubility of thallium(I) chloride in 0.40 M NaCl at 25°C. Ksp for TlCl is
A) 6.8 × 10-5 M
B) 4.2 × 10-4 M
C) 8.2 × 10-3 M
D) 1.3 × 10-2 M
23) In which of the following solutions would solid PbBr2 be expected to be the least soluble at
25°C?
A) 0.1 M HBr
B) 0.1 M NaBr
C) 0.1 M CaBr2
D) 0.1 M K NO3
24) What is the molar solubility of AgCl in 0.20 M NH3? Ksp for AgCl is and Kf for
Ag(NH3)2+ is
A) 1.3 × 10-5 M
B) 1.0 × 10-2 M
C) 1.1 × 10-2 M
D) 5.5 × 10-2 M
25) 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 1.0 × 1021.
A) 0.050 M
B) 0.10 M
C) 0.20 M
D) 0.40 M
26) 0.10 M potassium chromate is slowly added to a solution containing 0.50 M AgNO3 and
0.50 M Ba(NO3)2. What is the Ag+ concentration when BaCrO4 just starts to precipitate? The
Ksp for Ag2CrO4 and BaCrO4 are 1.1 × 10-12 and respectively.
A) 6.5 × 10-5 M
B) 1.3 × 10-4 M
C) 3.2 × 10-4 M
D) 6.8 × 10-2 M
15.3 Short Answer Questions
1) The balanced net ionic equation for the neutralization reaction involving equal molar amounts
of HNO3 and KOH is ________.
2) The balanced net ionic equation for the neutralization reaction involving equal molar amounts
of
HCl and CH3CH2NH2 is ________.
3) The solution formed upon adding 50.00 mL of 0.10 M NH4Cl to 50.00 mL of 0.10 M NH3
will have a pH that is ________ the pH of the original NH3 solution.
4) A buffer prepared by mixing 50.00 mL of 0.10 M HF with 50.00 mL of 0.10 M NaF will have
a pH that is ________ 7.0.
5) A buffer prepared by mixing equal moles of an acid having Ka = 4.5 × 10–4 and a salt of its
conjugate base has a pH = ________.
6) The addition of ________ mL of 0.1500 M NaOH is required to titrate 25.00 mL of 0.2250 M
HCl to the equivalence point, which occurs at a pH of ________.
7) The half equivalence point in the titration of 0.100 M HCO2H (Ka = 1.8 × 10–4) with 0.250
M NaOH occurs at pH = ________.
8) The half equivalence point in the titration of 0.100 M CH3NH2 (Kb = 3.7 × 10–4) with 0.250
M HCl occurs at pH = ________.
9) Selenous acid, H2SeO3 has acid dissociation constants Ka1 = 3.5 × 10–2 and Ka2 = 5 × 10–8.
When 25.00 mL of 0.100 M selenous acid is titrated with 0.200 M NaOH the first equivalence
point occurs at pH = ________.
10) At 25°C calcium fluoride has a solubility product constant Ksp = 3.0 × 10–11. The solubility
of CaF2 at this temperature is ________ mol/L.