Tasks and exercises

 

1.      From what acid and what base were the following salts made: CaSO4, NH4Br, and BaCl2?

2.      Tell whether 0.1 M solutions of the following salts would be acidic, neutral, or basic: BaCl2, CuS04, (NH4)2S04, ZnCl2, NaCN.

3.      How should the pH of a 0.1 M solution of NaC2H302 compare with that of a 0.1 M solution of KC2H302? Explain briefly.

4.       What is the pH of a 0.1 mol/L solution of NaCN?

5.      Calculate the [OH-], pOH and pH of these solutions:  a) 0.50 mol/L KCN; b) 0.20 mol/L NaClO.

6.      Calculate the pH of a 0.20 M solution of ammonium chloride, Kb = 1.8 × 10–5.

7.      A 0.02 M solution of sodium acetate in water at 25°C has a hydrogen ion concentration of 3 × 10–9 M. What is the hydrolysis constant of the salt?

8.      Calculate the pH of a decinormal solution of ammonium chloride. (pKa = 5.7 and pKw = 14

9.      20 ml of 0.2 M NaOH solution be treated with 40 ml of 0.2 M acetic acid solution to give 70 ml. Calculate the pH of the solution.

10.  Aniline is an amine that is used to manufacture dyes. It is isolated as aniline hydrochloride, [C6H5NH3+]Cl, a salt prepared by the reaction of the weak base aniline and hydrochloric acid. What is the pH of a 0.233 M solution of aniline hydrochloride?

C6H5NH3+ (aq) + H2O (l) → H3O+ (aq) + C6H5NH2 (aq)