What is the pH of the solution obtained by mixing 30.00 mL of 0.250 M HCl and 30.00 mL of 0.125 M NaOH? We assume additive volumes. What is the pH of a solution that is 0.75 M in sodium acetate and 0.50 M in acetic acid? (ka for acetic acid is 1.3×105.) Calcualte the pH of a solution prepared by mixing 15.00 ml of 0.10 M NaOH and 30.00 mL of 0.10 M benzoic acid solution. (Benzoic acid is monoprotic; its dissociation constant is 6.3×105.) Assume additive volumes.