What is the pH of a buffer that results when 0.50 mole of Na3PO4 is mixed with 0.75 mole of HCl and diluted with water to 1.00 L? (The acid dissociation constants for phosphoric acid are Ka1 = 7.5 * 10^-3, Ka2 = 6.2 *10^-8, and Ka3 = 3.6 * 10^-13) can you show me the steps with plunging in the numbers please. I would appreciate it