A 0.84 liter buffer solution is prepared so that it is 0.420 M in benzoic acid (C6H5COOH) and 0.630 M in sodium benzoate (C6H5COONa). If you add 15.80 mL of a 3.33 M solution of nitric acid to this buffer solution, what is the final pH? The Ka for benzoic acid = 6.5 X 10-5.