17. Acid and Base Equilibrium
Triprotic Acids and Bases Calculations
3PRACTICE PROBLEM
Commonly found in cola drinks, phosphoric acid (H3PO4) is a triprotic acid. If a sample of cola has a pH of 2.80 and the total concentration of phosphoric acid species is 0.500 M, what are the concentrations of H3PO4, H2PO4-, HPO42-, and PO43-? The Ka values for phosphoric acid are: Ka1 = 7.5 x 10-3, Ka2 = 6.2 x 10-8, and Ka3 = 4.8 x 10-13.
Commonly found in cola drinks, phosphoric acid (H3PO4) is a triprotic acid. If a sample of cola has a pH of 2.80 and the total concentration of phosphoric acid species is 0.500 M, what are the concentrations of H3PO4, H2PO4-, HPO42-, and PO43-? The Ka values for phosphoric acid are: Ka1 = 7.5 x 10-3, Ka2 = 6.2 x 10-8, and Ka3 = 4.8 x 10-13.