At 25 degrees C phosphoric acid, H3PO4, has the following equilibrium constants: Ka1 = 7.5 X 10-3 Ka2 = 6.2 X 10-8 Ka3 = 4.2 X 10-13 a)What is the pH of a solution of 0.700 M K2HO4, potassium hydrogen phosphate? b)What is the pH of a solution of 0.450 M KH2PO4, potassium dihydrogen phosphate?