1. A buffer solution:

A. resists large changes in pH.

B. is generally a mixture of a strong acid and a strong base.

C. is generally a mixture of a weak acid and its conjugate base.

D. Both A and B are true.

E. Both A and C are true.

2. If some NH4Cl (s) is added to an aqueous solution of NH3 (aq):
A. the pH of the solution will increase.

B. the pH of the solution will decrease.

C. the pH of the solution will not change.

D. the solution will have no pH.

3. In an acid/base titration, the greatest change in pH usually occurs:
A. at the beginning of the titration.

B. in the buffer region.

C. near the equivalence point.

D. after the equivalence point.

4. What is the expression for Ksp for Pb3(PO4)2 ?

A. Ksp = [Pb2+] [PO43-]

B. Ksp = [Pb2+]3[PO43-]2

C. Ksp = [Pb2+]2[PO43-]3

D. Ksp = [Pb2+]3[PO43-]

E. Ksp = [Pb2+] [PO43-]2

5. Which of the following WOULD NOT be considered a buffer solution?

A. 0.1 M HC2H3O2 mixed with 0.1 M NaC2H3O2 in equal amounts.

B. 0.1 M NH3 mixed with 0.1 M NH4Cl in equal amounts.

C. 0.1 M H2SO3 mixed with 0.1 M NaHSO3 in equal amounts.

D. 0.1 M HNO3 mixed with 0.1 M NaNO3 in equal amounts.

E. All would be considered buffers.

6. Which of the following solid salts is more soluble in 1.0 M HCl than in pure water?

A. NaClO4

B. KCl

C. FePO4

D. AgCl

E. KNO3

7. When 2.00 mmole of HCl (aq) reacts with 3.00 mmoles of Na2CO3 (aq), the primary

species remaining in solution are:

A. H3O+ , CO32- , and H2O

B. H3O+ , HCO3- , and H2O

C. HCO3- , CO32- , and H2O

D. OH- , CO32- , and H2O

E. H3O+ , OH- , and H2O

8. The term "formation constant" refers to:
A. an acid/base equilibrium constant

B. a solubility equilibrium constant

C. a complex ion equilibrium constant

D. a precipitation formation reaction

E. the common ion effect

9. When speaking of complex ions, a ligand is

A. a metal ion which bonds with a lewis base.

B. a lewis base which bonds with a metal ion.

C. a metal ion which bonds with a lewis acid.

D. a lewis acid which bonds with a metal ion.

E. sort of like a tendon, but it attaches bones to each other.

10. Which of the following is an example of the "Common Ion Effect":

A. H3O+ reacts with a strong base to produce water.

B. H3O+ suppresses the ionization of a weak acid with which it is mixed.

C. H3O+ improves the solubility of Ag(OH)2 in a solution.

D. All of these

E. None of these

11. Which of the following shows the reaction corresponding to the Ksp of Fe2(CO3)3 ?

A. Fe2(CO3)3 (s) Fe2O3 (s) + 3 CO2 (g)

B. 2 Fe3+ (aq) + 3 CO32- (aq) Fe2(CO3)3 (s)

C. Fe2O3 (s) + 3 CO2 (g) Fe2(CO3)3 (s)

D. Fe2(CO3)3 (s) 2 Fe3+ (aq) + 3 CO32- (aq)

E. 2 Fe (s) + 3 C (s) + 3 O3 (g) Fe2(CO3)3 (s)

12. Which of the following shows the net ionic equation between solutions of

benzoic acid (HC7H6O2 , Ka = 6.3 x 10-5) and NaOH :

A. H3O+ (aq) + OH- (aq) H2O (l) + H2O (l)

B. H3O+ (aq) + C7H6O2- (aq) HC7H6O2 (aq) + H2O (l)

C. HC7H6O2 (aq) + NaOH (aq) H2O (l) + NaC7H6O2 (aq)

D. C7H6O2- (aq) + OH- (aq) H2O (l) + C7H5O22- (aq)

E. HC7H6O2 (aq) + OH- (aq) H2O (l) + C7H6O2- (aq)

For questions 13 through 15, use the following data:

Compound
Solubility Product (Ksp)
BaSO4
1.5 x 10-9
CoS
5.0 x 10-22
PbSO4
1.3 x 10-8
AgBr
5.0 x 10-13
BaCO3
5.0 x 10-9

13. Which of the substances above would have the smallest molar solubility in water?

A. BaSO4 B. CoS C. PbSO4 D. AgBr E. BaCO3

14. Which of the substances above would have solubility least affected by pH changes?

A. BaSO4 B. CoS C. PbSO4 D. AgBr E. BaCO3

15. Which of the substances above would have a lower solubility in a 0.10 M Na2S (aq) solution than in pure water?

A. BaSO4 B. CoS C. PbSO4 D. AgBr E. none of these

16. Benzoic acid (HC7H6O2 ) has Ka = 6.3 x 10-5 . A buffer solution made from equal amounts of HC7H6O2 and NaC7H6O2 would have a pH near:

A. 9.8

B. 8.4

C. 6.3

D. 5.7

E. 4.2

For questions 17 through 18 , consider the following titration:

25.0 mL of 0.100 M HNO2 (aq) is placed in an Erlenmeyer flask and is carefully titrated with 0.200 M NaOH (aq)

17. How many mL of the NaOH solution are required to reach the "equivalence point" of the titration?

A. 25.0

B. 50.0

C. 12.5

D. 2.50

E. 8.00

18. Which of the following best describes the pH at the "equivalence point" of this titration?

A. pH < 7 B. pH > 7 C. pH = 7 D. pH = pKa E. pH = pKb

19. 10.0 mL of 0.10 M NaOH is added to 100 mL of a solution which contains 3.00 mmoles of HC2H3O2 and 1.00 mmoles of NaC2H3O2 , what is the pH of the resulting mixture?

A. 5.0

B. 4.7

C. 5.2

D. 4.3

E. 4.6

20. What is the molar solubility of PbSO4 ? (Ksp for PbSO4 = 1.3 x 10-8)

A. 1.3 x 10-8

B. 1.5 x 10-3

C. 2.6 x 10-8

D. 8.1 x 10-5

E. 1.1 x 10-4

21. What is the pH of a solution prepared by mixing 200. mL of 0.1 M HCl (aq) and

200. mL of 0.1 M HF (aq)?

A. 1.0

B. 1.3

C. 2.2

D. 3.1

E. 5.0

22. What will be the pH at the equivalence point of a titration of 50.0 mL of

0.00812 M Ba(OH)2 with 0.1000 M HCl (aq)?

A. 6.0

B. 7.0

C. 8.0

D. 9.0

E. 12.2

23. What is the pH of a solution prepared by mixing 25.0 mL of 0.10 M HC2H3O2 (aq) with

15.0 mL of 0.10M NaOH?

A. 4.3

B. 4.6

C. 4.7

D. 4.9

E. 7.0

24. What is the pH of a solution prepared by mixing 25.0 mL of 0.10 M HCl (aq) with

50.0 mL of 0.10 M NaOH (aq)?

A. 1.3

B. 7.2

C. 8.9

D. 12.5

E. 12.7

25. The Ksp of Mn(OH)2 is 2.0 x 10-13. At what pH will Mn(OH)2 begin to precipitate in a solution which has an initial Mn2+ concentration of 0.10 M?

A. 6.5

B. 13

C. 5.8

D. 7.0

E. 8.2

26. The solubility of Cu(IO3)2 is reported as 1.2 g/L of solution. What is the solubility

product (Ksp ) for this salt? (Molar Mass of Cu(IO3)2 = 413.4 )

A. 9.8 x 10-8

B. 8.6 x 10-7

C. 7.3 x 10-6

D. 6.4 x 10-5

E. 1.2 x 10-4

27. Zn2+ ions can be complexed by NH3 to form Zn(NH3)42+ where Kf = 3.8 x 109.

What would be the concentration of "uncomplexed Zn2+ " in a solution that is

0.200 M Zn(NH3)42+ ?

A. 2.9 x 10-3 M

B. 8.8 x 10-3 M

C. 6.7 x 10-4 M

D. 2.0 x 10-13 M

E. 1.2 x 10-5M