This is my question: When a 17.9 mL sample of a 0.493 M aqueous nitrous acid solution is titrated with a 0.476 M aqueous barium hydroxide solution, what is the pH after 13.9 mL of barium hydroxide have been added? I'm not really sure how to start it? I have the moles of the acids and the base. [acid]=8.8247E-3 [base]=6.6164E-3 but after that I'm lost! Help would be greatly appreciated!