Phosphoric acid is a triprotic acid with the p K a pKa values p K a 1 = 2.148 pKa1=2.148 , p K a 2 = 7.198 pKa2=7.198 , and p K a 3 = 12.375 pKa3=12.375 . You wish to prepare 1.000 L of a 0.0300 0.0300 M phosphate buffer at pH 7.460 7.460 . To do this, you choose to mix the two salt forms involved in the second ionization, NaH 2 PO 4 NaH2PO4 and Na 2 HPO 4 Na2HPO4 , in a 1.000 L volumetric flask and add water to the mark. What mass of each salt will you add to the mixture?