autoionization of water - dissociation of H 2 O molecules to H + and OH - ions The lager the K a the stronger the acid equilibrium at which base reacts with H 2 O to form a conjugate acid and OH - whe...autoionization of water - dissociation of H 2 O molecules to H + and OH - ions The lager the K a the stronger the acid equilibrium at which base reacts with H 2 O to form a conjugate acid and OH - when two reactions are added together then equilibrium constant of third reaction is equal to the product of the equilibrium constants of the added reactions K a x K b = [H + ][OH - ] = K w = 14; (pK a = -log K a and pK b = -log K b )