Princeton 2012/Barron 4th ed.
AP Practice Problems
Unit 13 – Acids & Bases
Multiple Choice (no calculator)
31. This equilibrium constant always has
a value of 1×10-14 at 25°C. (P10.2)
a. Kc
b. Kp
c. Ka
d. Kw
e. Ksp
34. Which of the following CANNOT
occur together in solution? (B14.6)
a. H3PO4 and H2PO4b. HCO3- and CO3-2
c. Na+ and SO4-2
d. C2O4-2 and H2C2O4
e. HPO4-2 and PO4-3
32. If the acid dissociation constant for
HCrO4- is Ka and the solubility
product for CaCrO4 is Ksp, which of
the following expressions gives the
equilibrium expression for the
reaction below? (P10.13)
35. pH is equal to pKa (B14.9)
a. when [acid] = [conjugate
base]
b. at the end point of a titration
c. in the buffer region
d. in the Henderson-Hasselbalch
equation
e. at equilibrium
HCrO4- + Ca+2 ↔ H+ + CaCrO4
a.
b.
c.
d.
e.
KaKsp
Ka/Ksp
Ksp/Ka
1/KspKa
KaKsp/2
33. Silver hydroxide will be LEAST
soluble in a solution with a pH of
(P9.26)
a. 3
b. 5
c. 7
d. 9
e. 11
36. Which of the following statements is
correct? (B14.13)
a. HClO2 is a stronger acid than
HClO3.
b. HI is a weaker acid than HCl.
c. CH3COOH is a stronger acid
than CH2BrCOOH.
d. HNO3 is a stronger acid than
HNO2.
e. H3PO4 is a stronger acid than
HClO4.
37. The only acid that is both a strong
and a weak acid on dissociation is
a. Hydrochloric acid
b. Perchloric acid
c. Nitric acid
d. Sulfuric acid
e. Phosphoric acid
Princeton 2012/Barron 4th ed.
Essay
1. The acid dissociation constants for the reactions below are given at 25°C. (P10.2)
H2CO3 ↔ H+ + HCO3HCO3- ↔ H+ + CO3-2
K1 = 4.3×10-7
K2 = 5.6×10-11
a. What is the pH of a 0.050 M solution of H2CO3 at 25°C?
b. What is the concentration of CO3-2 ions in the solution in (a)?
c. How would the addition of each of the following substances affect the pH of the
solution in (a)?
i. HCl
ii. NaHCO3
iii. NaOH
iv. NaCl
d. What is the value of Keq for the following reaction?
H2CO3 ↔ 2H+ + CO3-2
Princeton 2012/Barron 4th ed.
Answers – Acids & Bases
Multiple Choice
1. B
2. D
3. E
4. B
5. B
6. A
7. B
8. E
9. A
10. E
11. A
12. C
13. E
14. B
15. B
16. E
17. A
18. C
19. C
20. D
21. A
22. A
23. D
24. C
25. C
26. D
27. D
28. A
29. E
30. E
31. D
32. B
33. E
34. D
35. A
36. D or B
37. D
Essay
1.
a. 3.8
b. 5.6×10-11
c. i. decrease pH (increase H+) ii. increase pH (decrease H+) iii. decrease pH
(increase H+) iv. no effect
d. 2.4×10-17 (multiply K1×K2)