acid dissociation constant (acid ionization constant)

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(Ka) Compare with base hydrolysis constant .The equilibrium constant for the dissociation of an acid into a hydrogen ion and an anion. For example, the acid dissociation constant for acetic acid is the equilibrium constant for HC2H3O2(aq) H+(aq) + C2H3O2-(aq), which is Ka = [H+][C2H3O2-]/[HC2H3O2].