1. A buffer with a pH of 4.49 contains 0.35 M of sodium benzoate and 0.18 M of benzoic acid. What is the concentration of [H3O+] in the solution after the addition of 0.054 mol HCl to a final volume of 1.3 L? Assume that any contribution of HCl to the volume is negligible.

2. What volume of 3.50 M NaOH would be required to increase the pH to 4.93 ?