Question

What is the acid dissociation constant (Ka) for the reaction of carbonic acid (H2CO3) with water?

Answer 1

Ka1 = [H3O+][HCO3-] / [H2CO3]

Ka2 = [H3O+][CO32-] / [HCO3-]

Step-by-step explanation:

diprotic acid:

• H2CO3 + H2O ↔ H3O+ + HCO3-

∴ Ka1 = [H3O+][HCO3-] / [H2CO3]

• HCO3- + H2O ↔ H3O+ + CO32-

∴ Ka2 = [H3O+][CO32-] / [HCO3-]