1

Review on Chapter 16

Circle the correct answer

2

1. Which of the following is not a characteristic property of bases?

A. taste bitter

B. turn litmus from pink to blue

C. neutralize acids

D. react with carbonates to produce carbon dioxide gas

E. feel slippery

3

2. When 10.0 mL of a solution of a strong acid at pH = 2.50 is mixed with 10.0 mL of a strong acid at pH = 6.50, what is the pH of the resulting solution?

A) 5.50B) 8.50C) 3.80D) 4.50E) 2.80

4

3. Which, if any, of the following will not form a basic solution when dissolved in water?

A) NaOH

B) Ca(OH)2

C) CH3OH

D) N(CH3)3

E) All of the above will form basic aqueous solutions.

5

4. Calculate the hydroxide ion concentration of a solution if its pH is 6.389.

A) 1.00 x 10-14 mol/L

B) 4.08 x 10-7 mol/L

C) 9.92 x 10-7 mol/L

D) 2.45 x 10-8 mol/L

E) none of the above

6

5. What is the pH of a 675 mL aqueous solution containing 0.036 mol of NaOH?

A) 3.41

B) 10.58

C) 12.73

D) 1.27

E) 13.00

7

6. What is the hydronium ion concentration in a solution with a pH of 2.80?

A) 6.3 x 102 mol/L

B) 1.6 x 10-3 mol/L

C) 6.3 x 10-2 mol/L

D) 4.8 x 10-8 mol/L

E) 5.0 x 10-7 mol/L

8

7. Consider the reaction of the base, ammonia (NH3), with water. The conjugate acid of NH3 is

A) H3O+

B) NH4+

C) NH2-

D) OH-

E) NH2+

9

8. Which of the following is a correct description of the natural direction of a Brønsted-Lowry acid-base reaction?

A) weaker acid + weaker base → stronger acid + stronger base

B) weaker acid + stronger base → stronger acid + weaker base

C) stronger acid + weaker base → weaker acid + stronger base

D) stronger acid + stronger base → weaker acid + weaker base

E) None of the above statements is always correct.

10

9. Which of the following pairs of species is not a conjugate acid-base pair?

A) HCl and H+

B) HSO4- and SO42-

C) H2SO4 and HSO4-

D) H2O and OH-

E) NH3 and NH2-

11

10. For which one of the following reactions is the equilibrium constant Kc > 1?

A. CH3COOH + H2O → CH3COO- + H3O+

B. CH3COOH + OH- → CH3COO- + H2O

C. NH4+ + H → NH3 + H2

+

D. Cl- + H2O → HCl + OH-

E. HSO4- + H3O+ → H2SO4 + H2O

12

11. Calculate the acid-dissociation constant (Ka) for a weak acid (HA) if a 0.50 M HA solution has a hydronium ion concentration of 3.0 x 10-4M.

A) 6.0 x 10-4

B) 5.0 x 10-6

C) 9.0 x 10-8

D) 6.0 x 10-6

E) 1.8 x 10-7

13

12. What is the pH of a 0.20 M CH3COOH (acetic acid) solution? (Ka = 1.8 x 10-5)

A) 5.4

B) 2.7

C) 5.7

D) 2.0

E) 4.0

14

13. Calculate Ka for a monoprotic acid whose 0.30 M solution has a pH of 2.32. HA + H2O → H3O+ + A-

A) 4.8 x 10-3

B) 2.3 x 10-5

C) 7.6 x 10-5

D) 6.9 x 10-6

E) none of the above

15

14. Calculate the [HS-] of a 0.33 mol/L solution of H2S (Ka1 = 9.0 x 10-8; Ka2 = 1.0 x 10-17).

A) 3.0 x 10-8 mol/L

B) 9.0 x 10-8 mol/L

C) 1.7 x 10-4 mol/L

D) 3.0 x 10-4 mol/L

E) 8.1 x 10-15 mol/L

16

15. Ascorbic acid is a diprotic acid, H2As, where As2- is the ascorbate ion. What is the ascorbate ion concentration in a 0.1 mol/L solution of H2As? (Ka1 = 8.0 x 10-5, Ka2 = 3.0 x 10-12)

A. 3.0 x 10-12 mol/LB. 8.0 x 10-5 mol/LC. 5.5 x 10-7 mol/LD. 3.0 x 10-6 mol/LE. 1.7 x 10-6 mol/L

17

16. Calculate the pH of a 0.450 M solution of NH4Cl (Kb for NH3 is 1.8 x 10-5).

A) 4.45

B) 2.52

C) 5.60

D) 4.80

E) 9.60

18

17. In a 0.100 M HF solution, the percent dissociation is determined to be 9.5%. Calculate the Ka for HF based on this data.

A) 9.5 x 10-2

B) 1.0 x 10-3

C) 3.1 x 10-3

D) 7.6 x 10-4

E) 9.5 x 10-4

19

18. A 0.20 M NH3 solution is 1.7 % ionized. Calculate the H+ concentration. NH3 + H2O → NH4

+ + OH-

A) 2.9 x 10-12 M

B) 3.4 x 10-3 M

C) 2.9 x 10-14 M

D) 0.17 M

E) 0.20 M

20

19. What is the pH of a solution prepared from 0.250 mol of NH3 dissolved in sufficient water to make 1.00 L of solution? (Kb = 1.8 x 10-5)

A) 2.12B) 2.67C) 8.92D) 11.33E) 13.40

21

20. Which, if any, of the following is not a strong acid in water?

A) HF

B) HBr

C) HCl

D) HI

E) All four are strong acids in water.

22

21. Consider each of the following pairs of acids. Which statement is correct?

A) HClO2 is a stronger acid than HClO4.

B) H2SO4 is a stronger acid than H2SeO4.

C) H2O is a stronger acid than HF.

D) H2S is a stronger acid than H2Se.

E) HS- is a stronger acid than H2S.

23

22. Which of the following statements about acids and bases is incorrect?

A) The strongest acid that can exist in water is H3O+.

B) All strong acids in water are leveled to the same strength.

C) Any base which is stronger than OH- will react with water to produce OH-.

D) The relative strength of strong acids can be measured by using a solvent which is a weaker base than water.

E) The oxide ion is a weaker base than OH-.

24

23. An acid HA has a Ka of 10-7. What is the pH of a 0.1 M solution of its conjugate base?

A) 5.0

B) 7.0

C) 8.0

D) 10.0

E) 13.0

25

24. Consider each of the following pairs of acids. Which statement is correct?

A) HClO is a stronger acid than HClO3.

B) H2SO3 is a stronger acid than H2SO4.

C) NH3 is a stronger acid than H2O.

D) HBr is a stronger acid than H2S.

E) CCl3COOH is a stronger acid than CF3COOH.

26

25. Consider the reaction CH3NH2 + H2O CH3NH3+ + OH- where

CH3NH2 is methylamine and CH3NH3+ is the methylammonium ion.

Select the correct description of this reaction in terms of Lewis acid-base theory.

A) Methylamine serves as a Lewis acid in the forward reaction and methylammonium ion serves as a Lewis base in the reverse reaction.

B) Water serves as a Lewis base in the forward reaction and the hydroxide ion serves as a Lewis base in the reverse reaction.

C) Methylamine serves as a Lewis base in the forward reaction and hydroxide ion serves as a Lewis acid in the reverse reaction.

D) Water serves as a Lewis acid in the forward reaction and methylammonium ion serves as a Lewis base in the reverse reaction.

E) Methylamine serves as a Lewis base in the forward reaction and hydroxide ion serves as a Lewis base in the reverse reaction.

27

26. Which of the following substances when dissolved in water will form an acid aqueous solution?

A) KI

B) Ba(OH)2

C) CH3COONa

D) NH4Cl

E) NaF

28

27. Which of the following substances when dissolved in water will form a basic aqueous solution?

A) KBr

B) CH3CO2Na

C) BaCl2D) NO2

E) (CH3)3NHCl

29

28. Which, if any, of the following is an example of the leveling effect?

A) The concentrations of H+ and OH- in pure water are equal.

B) The number of strong acids equals the number of strong bases.

C) The number of strong acids equals the number of weak acids.

D) In water, no acid stronger than H3O+ can exist.E) None of the above is an example of the leveling

effect.

30

29. Which of the following reactions illustrate Al(OH)3 acting as a Lewis acid?

A) Al(OH)3 → Al3+ + 3OH-

B) Al(OH)3 + OH- → Al(OH)2O- + H2O

C) Al(OH)3 + OH- → Al(OH)4-

D) Al(OH)3 + 3H+ → Al3+ + 3H2O

E) Al3+ + 3OH- → Al(OH)3

31

Which of the following is most likely to act as a Lewis acid?

A) NH3

B) F-

C) H2O

D) BF4-

E) Zn2+