Dissociation constant

In chemistry and biochemistry the dissociation constant, abbreviated K_d, is a measure of the extent to which a dissociation reaction

AB ↔ A + B

proceeds at equilibrium.

It is given quantitatively by the expression

K_d = [A]×[B]×[AB]^-1

Where [A], [B], and [AB] indicate the concentrations of A, B, and AB, respectively.

See also hydrogen bond.

The dissociation constant is a specific type of equilibrium constant[?].

The dissociation constant of water (Ke) varies in function of the temperature. The value of pH for neutrality is not the same at different temperatures.