2. A 0.10 mol/L solution of a weak acid was found to be 4.0% dissociated. Calculate Ka. (5 marks)

3. Calculate the pH of a 0.10 mol/L solution of ascorbic acid, H2C6H6O6 (aq) and the
equilibrium concentration of H2C6H6O6, HC6H6O6^-(aq) and C6H6O6^2- (aq). Ascorbic acid
is a polyprotic acid. (8 marks)

4. What is the value of the base ionization constant, Kb, for the acetate ion, C2H3O2^- (aq).
(3 marks)

5. Calculate the pH of a 0.100 mol/L aqueous solution of hydrazine, N2H4(aq), a weak
base. The kb for hydrazine is 1.7 x 10^-6. (5 marks)​