Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
Chapter 16
Acid-Base Equilibria and Solubility Equilibria
1. In which one of the following solutions will acetic acid have the greatest percent
ionization?
2. Which one of the following is a buffer solution?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
3. Which one of the following combinations cannot function as a buffer solution?
4. Which of the following is the most acidic solution?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
5. Which of the following yields a buffer solution when equal volumes of the two solutions
are mixed?
6. Which of the following yields a buffer solution when equal volumes of the two solutions
are mixed?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
7. Which of the following yields a buffer solution when equal volumes of the two solutions
are mixed?
8. Which of the following yields a buffer solution when equal volumes of the two solutions
are mixed?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
9. Calculate the pH of a buffer solution that contains 0.25 M benzoic acid (C6H5CO2H) and
0.15M sodium benzoate (C6H5COONa). [Ka = 6.5 10–5 for benzoic acid]
10. A solution is prepared by mixing 500. mL of 0.10 M NaOCl and 500. mL of 0.20 M
HOCl. What is the pH of this solution? [Ka(HOCl) = 3.2 10–8]
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
11. Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid
(HCNO) and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of
solution.
[Ka(HCNO) = 2.0 10–4]
12. Calculate the pH of a solution that is 0.410 M in HOCl and 0.050 M in NaOCl. [Ka(HOCl)
= 3.2 10–8]
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
13. Calculate the pH of a buffer solution prepared by dissolving 0.2 mole of sodium cyanate
(NaCNO) and 1.0 mole of cyanic acid (HCNO) in enough water to make 1.0 liter of solution.
[Ka(HCNO) = 2.0 10–4]
14. You are asked to go into the lab and prepare an acetic acid – sodium acetate buffer
solution with a pH of 4.00 0.02. What molar ratio of CH3COOH to CH3COONa should be
used?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
15. What is the net ionic equation for the reaction that occurs when small amounts of
hydrochloric acid are added to a HOCl/NaOCl buffer solution?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
16. Consider a buffer solution prepared from HOCl and NaOCl. Which is the net ionic
equation for the reaction that occurs when NaOH is added to this buffer?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
17. Within what pH range is a HOCl – NaOCl buffer effective?
18. Assuming equal concentrations of conjugate base and acid, which one of the following
mixtures is suitable for making a buffer solution with an optimum pH of 9.2–9.3?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
19. Assuming equal concentrations of conjugate base and acid, which one of the following
mixtures is suitable for making a buffer solution with an optimum pH of 4.6–4.8?
20. You have 500.0 mL of a buffer solution containing 0.20 M acetic acid (CH3COOH) and
0.30 M sodium acetate (CH3COONa). What will the pH of this solution be after the addition
of 20.0 mL of 1.00 M NaOH solution? [Ka = 1.8 10–5]
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
21. You have 500.0 mL of a buffer solution containing 0.30 M acetic acid (CH3COOH) and
0.20 M sodium acetate (CH3COONa). What will the pH of this solution be after the addition
of 20.0 mL of 1.00 M NaOH solution? [Ka = 1.8 10–5]
22. Starting with 0.250L of a buffer solution containing 0.250 M benzoic acid (C6H5COOH)
and 0.20 M sodium benzoate (C6H5COONa), what will the pH of the solution be after the
addition of 25.0 mL of 0.100M HCl? (Ka (C6H5COOH) = 6.5 x 10-5)
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
23. Starting with 0.750L of a buffer solution containing 0.30 M benzoic acid (C6H5COOH)
and 0.35 M sodium benzoate (C6H5COONa), what will the pH of the solution be after the
addition of 340.0 mL of 0.350M HCl? (Ka (C6H5COOH) = 6.5 x 10-5)
24. Calculate the percent ionization of cyanic acid, Ka = 2.0 10–4, in a buffer solution that is
0.50 M HCNO and 0.10 M NaCNO.
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
25. In which one of the following solutions will acetic acid have the greatest percent
ionization?
26.
Acid dissociation constants for phosphoric acid are given below.
A buffer with a pH = 7.4 can best be made by using
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
27. The pH at the equivalence point of a titration may differ from 7.0 due to
28. For which type of titration will the pH be basic at the equivalence point?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
29. For which type of titration will the pH be neutral at the equivalence point?
30. 25.0 mL of a 0.100 M solution of NH3 is titrated with 0.150M HCl. After 10.0 mL of the
HCl has been added, the resultant solution is:
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
31. 25.0 mL of a 0.100 M solution of NH3 is titrated with 0.250M HCl. After 10.0 mL of the
32. 25.0 mL of a 0.100 M solution of NH3 is titrated with 0.250M HCl. After 25.0 mL of the
HCl has been added, the resultant solution is:
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
33. 35.0 mL of a 0.250 M solution of KOH is titrated with 0.150 M HCl. After 35.0 mL of the
HCl has been added, the resultant solution is:
34. 40.0 mL of a 0.65 M solution of HF is titrated with 0.100 M NaOH. After 0.400 L of the
NaOH solution has been added, the resultant solution is:
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
35. 24.00 mL of a 0.25 M NaOH solution is titrated with 0.10M HCl. What is the pH of the
solution after 24.00 mL of the HCl has been added?
36. 35.00 mL of a 0.30 M HCl solution is titrated with 0.35 M NaOH. What is the pH of the
solution after 40.00 mL of the NaOH has been added?
Chapter 16 – Acid-Base Equilibria and Solubility Equilibria
37. 50.00 mL of 0.10 M HNO2 (nitrous acid, Ka = 4.5 10–4) is titrated with a 0.10 M KOH
solution. After 25.00 mL of the KOH solution is added, the pH in the titration flask will be
38. A titration of an acid and base to the equivalence point results in a noticeably acidic
solution. It is likely this titration involves