Principles of Chemistry IICHEM 1212Chapter 15

1. List some general properties of acids and bases.

2. Define Bronsted-Lowry acids and bases. How do the Bonsted-Lowry definitions differ from Arrhenius definitions of acids and bases?

3. Give an example of a conjugate pair in an acid-base reaction.

4. Classify the following as Bronsted-Lowry acid or base, or both: H2O, OH-, H3O+, NH3, HCN, NH2-, NO3-, NH4+, H2PO4-, CO32-, and HBr.

5. Write the formula for each of the following:

a) Conjugate base of H2SO3, NH4+, H2S, HIO4, CH2ClCOOH, H2PO4-, HPO42-, HS-, HClO, H2S

b) Conjugate acid of OH-, CN-, HPO42-, SO42-, HS-, CO32-, ClO-, HS-, HCO32-,

6. Identify the acid-base pair in each of the following reactions:

CH3COO- + HCN ↔ CH3COOH + CN-

HCO3- + HCO3- ↔ H2CO3 + CO32-

H2PO4- + NH3 ↔ HPO42- + NH4+

CO32- + H2O ↔ HCO3- + OH-

7. Write a balanced chemical equation to represent each of the following acid-base neutralization reactions:

a) H3PO4 and KOHb) HNO3 and NaOHc) H2SO4 and Ca(OH)2

8. Calculate the hydronium ion concentration, [H3O+], given the following hydroxide ion concentrations, [OH-]. Indicate whether each of the solutions is acidic, basic, or neutral.

a) 2.5 x 10-3 Mb) 1.2 x 10-11 Mc) 5.2 x 10-10 Md) 3.7 x 10-4 M

9. Calculate the hydroxide ion concentration, [OH-], given the following hydronium ion concentrations, [H3O+]. Indicate whether each of the solutions is acidic, basic, or neutral.

a) 5.2 x 10-3 Mb) 1.6 x 10-12 Mc) 3.4 x 10-10 Md) 4.5 x 10-5 M

10. Calculate the pH of each of the following solutions and indicate whether the solution is acidic, basic, or neutral:

a) [H3O+] = 3.4 x 10-10 Mb) [H3O+] = 2.6 x 10-2 M

c) [OH-] = 3.4 x 10-13 Md) [OH-] = 2.6 x 10-4 M

11. Calculate the pH of each of the following solutions:

a) 0.0010 M HClb) 0.76 M KOH

c) 2.8 x 10-4 M Ba(OH)2d) 5.2 x 10-4 M HNO3

12. Calculate the hydronium ion concentration in solutions with each of the following pH values:

a) 3.4b) 11.8c) 2.0d) 6.5e) 11.3

Determine the hydroxide ion concentration of each solution.

13. A 662-mL solution is made by dissolving 18.4 g of HCl in water. Calculate the pH of the solution.

14. How many grams of NaOH is needed to prepare 546 mL of solution with a pH of 10.00?

15. Calculate the number of moles of KOH in 5.50 mL of a 0.360 M KOH. What is the pOH of the solution?

16. What is Kb for the equilibrium CN- + H2O ↔ HCN + OH-

(Ka of HCN = 2.1 x 10-9)

17. Calculate the hydronium ion concentration in an aqueous 0.120 M nitrous acid

solution. The principal equilibrium is HNO2 + H2O ↔ H3O+ + NO2-

(Ka = 5.1 x 10-4).

18. Write the base hydrolysis reaction and calculate the Kb of hypochlorite (OCl-), given

that Ka for hypochlorous acid (HOCl) is 3.0 x 10-8.

19. Calculate the hydronium ion concentration in a 0.075 M NH3 solution. The

predominant equilibrium is NH3 + H2O ↔ NH4+ + OH-

20. Calculate the pH of 3.0 x 10-5 M Mg(OH)2, which completely dissociates in solution.

21. Calculate the pH and fraction of dissociation of a 0.0100 M solution of the weak acid

with Ka = 1.00 x 10-4.

22. Calculate the pH and fraction of association of a 0.0250 M solution of the weak base

with Kb = 1.00 x 10-10.

23. For propanoic acid (HC3H5O2, Ka = 1.3 x 10-5), determine the concentration of all species present, the pH, and the percent dissociation of a 0.100 M solution.

24. A solution is prepared by dissolving 0.56 g benzoic acid (C6H5CO2H, Ka = 6.4 x 10-5) in enough water to make 1.0 L of solution. Calculate [C6H5CO2H], [C6H5CO2-], [H+], [OH-], fraction of dissociation, and the pH of the solution.

25. The pH of a 1.00 x 10-2 M solution of cyanic acid (HOCN) is 2.77 at 25 oC. Calculate Ka for HOCN from this result.

26. Calculate the percent pyridine (C5H5N) that forms the pyridium ion (C5H5NH+), in a 0.10 M aqueous solution of pyridine (Kb = 1.7 x 10-9). What is the pH of this solution?

27. A 0.40 M solution of a monoprotic acid is 14 percent ionized. Calculate the ionization constant of the acid.

28. What is hydrolysis? Categorize salts according to how they affect the pH of a solution.

29. Specify which of the following salts will undergo hydrolysis: KF, NaNO3, NH4NO2, MgSO4, KCN, RbI, Na2CO3, CaCl2, HCOOK.

30. Predict the pH (>7, <7, or ≈7) of the aqueous solutions containing the following salts: KBr, Al(NO3)3, BaCl2, Bi(NO3)2.