CHEMISTRY 201 EXAM 2 REVIEW Chapters 16 and 17 SPRING 2008
Note: you will need to reference the Ka and Ksp tables in appendix D of your text.
1. Which of the following is a weak acid in aqueous solution? a) HNO3 b) HF c) H2SO4 d) HNO3
2. Which of the following salt solutions would be expected to have the highest pH ? a. NaCN(aq) b. NaClO4 (aq) c. NH4NO3 (aq) d. NaNO3 (aq) e. NaCl(aq)
3. What is the pH of a 0.08 M solution of benzoic acid ? 2.6
4. What is the pH of a 0.2 M solution of sodium propionate, NaC3H5O2 ? 9.1
5. A 0.10 M solution of a weak monoprotic acid has a pH of 3.30. What is its equilibrium constant, Ka? 2.5 E -6
6. For the following reaction, label each reactant as a Lewis acid or a Lewis base:
(Hint, it may be helpful to write out Lewis dot structures of the reactants )
BF
3
A + 2 : NH
3
B  BF
3
(NH
3
)
2
7. Calculate the pH of a 0.025 M Ba(OH)2 solution. 12.70
8. Label the Bronsted Lowry acids and bases in the following reaction:
H2O(l) A + CO3-2 (aq) B
 HCO3- (aq) + OH- (aq)
9. What is the pH of a 0.2 M solution of NH4Cl ? 5.0
10. What is the hydrolysis reaction of the acetate ion ? C2H3O2- + H2O

HC2H3O2 + OH-
11. Seawater has a pH of 8.10. What is its hydroxide ion concentration? 1.3 E-6 M
12. Which of the following mixtures is (are) suitable for making buffers?
a. HC7H5O2 and NaC7H5O2
b. NH3 and NH4Cl
c. HCl and NaCl
13. What is the pH of a sol which is 0.50 M in acetic acid and 0.10 M in sodium acetate? 4.05
14. All the following are acid-base conjugate pairs except a) OH-, O2- b) H2CO3, HCO3- c) HNO2, HNO3 d) HOCl, OCl- e. HSO4-, SO42-
15. Which of the following is the strongest acid?
a. HC2H3O2 b. HNO2 c. HCNO d. HClO e. HCN
16. Milk of magnesia has a pH of 10.40. What is its [H3O+]? 4.0 E-11
17. What is the acid dissociation reaction for HS- ? HS- + H2O

S2- + H3O+
18. A buffer solution is 0.15 M in acetic acid and 0.11 M in sodium acetate. What is the pH of the solution after the addition of 100.0 mL of 0.30 M of NaOH to 1.0 L of the buffer? 4.81
19. What is the pH of 0.010 M HNO3 ? 2.00
20. A diprotic acid, H2A, has Ka1 = 1.0 x 10 - 5 & Ka2 = 1.0 x 10 - 8. In a 0.10 M solution of
H2A what is [A2-]? 1.0 E -8 M
21. What is the pH of the diprotic acid solution described in the previous question? 3.00
22. What is the pH of a solution made by titrating 25 mL of 0.10 M HCl with 15 mL of 0.20 M
NaOH? 12.1
23. Which of the following is the most soluble in water? CoS HgS CuS MnS FeS Skip because you are missing some of the Ksp’s (you would pick the highest Ksp)
24. Calculate the molar solubility of AgCl at 25

C 1.3 E -5
25. A buffer is 0.10 M in NH3 and 0.10 M in NH4Cl. What is the pH of the solution after the addition of 10.0 mL of 0.20 M of HCl to 100.0 mL of the buffer? 9.08

26. What is the [ C2H3O2 - ] / [ HC2H3O2 ] ratio in a buffer of pH 5.00 ? 1.8
Describe how you might make an arbitrary volume of such a buffer starting with 0.50 M stocks of HC2H3O2 and
NaC2H3O2
You would use a vol of NaC2H3O2 that is 1.8 x that of the acid. So for
example, 180 mL of NaC2H3O2 and 100 mL of HC2H3O2
27. What is the pH of a buffer that is 0.15 M pyridine and 0.10 M pyridinium bromide ? 5.23
28. What is the solubility product expression (Ksp) for Zn
3
(PO
4
)
2
? Ksp = [Zn 2+ ] 3 [PO
4
3] 2
29. For Zn(OH)2 , Ksp = 2.1 x 10 - 16 . What is the molar solubility of Zn(OH)2 ? 3.7 E-6 M
30. The molar solubility for lead fluoride, PbF2 , is 2.1 x 10 - 3 moles / L at 25 C. Calculate the solubility product constant ( Ksp) for lead fluoride. 3.7 E-8
31. For Cu(OH)2 , Ksp = 2.6 x 10 - 19. What is the solubility of Cu(OH)2 in g / L ? 3.9 E-5g/L
32. Ksp for Pb3 (PO4)2 is 1 x 10-44. Two solutions are mixed, one containing Pb2+ and the other PO43-. If, at the instant of mixing, [Pb2+] is 1.0 x 10-6 M and [PO43-] is 1.0 x 10-8 M, does a precipitate form ? yes
33. The Ksp for AgI is 1 x 10 -1 6. In a solution that is 10- 3 M AgNO3 and 10 -3 M NaI a. AgI will precipitate.
b. no precipitation will occur. c. silver nitrate will precipitate. d. sodium iodide will precipitate. e. none of the above
34. What is the molar solubility of MgF2 in a 0.20 M NaF solution? (Ksp MgF2 = 8.0 x 10-8 )
2.0 E -6 M
35. Calculate the pH of each of the following points on a titration curve generate by titrating
10.0 mL of 0.100 M benzoic acid with 0.0800 M NaOH. a) 0 mL NaOH 2.60 d) total of 10.00 mL NaOH 4.80 b) total of 1.00 mL NaOH 3.14 c) total of 5.00 mL NaOH 4.02 e) total of 12.50 mL NaOH f) total of 15.00 mL NaOH
8.42
11.90 g) What volume of NaOH would be required to reach the half equivalence point? 6.25 mL
What is the pH at the half equivalence point? 4.20
36. Sketch a rough titration curve for malonic acid (H
2
C
3
H
2
O
4
) titrated against a strong base.
Indicate the location of the equivalence points on the curve. Indicate the location of the pKa’s on the vertical axis. See notes/ text for examples
37. The equivalence point on a weak base/ strong acid titration curves occurs at a pH: a) greater than 7 b) equal to 7 c) less than 7
38. Explain your answer to the previous question and illustrate it with an example reaction. See notes text for example/explanations.
39. When and how does pH effect the solubility of a low solubility salt? Give two examples: a low solubility salt that is more soluble in acid; a low solubility salt that is more soluble in base.
Write out reactions to illustrate your choices. See notes text for example/explanations.
40. Write out the reaction and expression (equation) for Kf for the formation of the complex ion
Ag(CN)
2
. Kf = [Ag(CN)
2
]/[Ag+][CN-] 2
41. In the following reaction, the formation of the species on the right side is favored:
HC2Cl3O2 + CHO2-  C2Cl3O2- + HCHO2
Which is the stronger acid, HC2Cl3O2 or HCHO2 ?
42. Write the chemical reaction for the base ionization of ethylamine, C2H5NH2
C2H5NH2 + H2O

C2H5NH3 + + OH-
43. You mix 50.0 mL of a 1.0 x 10 -2 M lead (II) nitrate solution with 50.0 mL of a 1.0 x 10 -2 M sodium fluoride solution. If a precipitate forms, what is its name and formula? Predict whether or not the ppt will form, assuming the volumes are additive (show your calculations).
PbF
2
lead (II) fluoride will ppt