Diapositive PPT
On peut donc supposer que [H3O+] et [OH-] seront tous deux négligeables devant C0.
E.N : [OH-] + [AH-] + 2 [A2-] = [H3O+ ] + C0
C.M.1 : [AH2] + [AH-] + [A2-] = C0
E.N - CM1 : [AH-] + 2 [A2-] - [AH2] - [AH-] - [A2-] = 0
pH = pKa1 + log { [AH-] / [AH2] }
pH = pKa2 + log { [A2-] / [AH-] }
2 pH = pKa1 + log { [AH-] / [AH2] } + pKa2 + log { [A2-] / [AH-] }