Note 182 — Chapter VI · CHEMICAL EQUILIBRIUM. THE LAW OF MASS ACTION

The equilibrium ratio, used as an illustration in the text, is the equilibrium ratio for monobasic acids. For polybasic acids, the ratio would have the form demanded by the rule given p. 94. For instance, for H2X ⇄ 2 H+ + X2−, the expression [H+]2 × [X2−] / [H2X] should be constant, provided the ionization occurs according to the law of chemical equilibrium in its simplest terms. In point of fact, for strong acids, this ratio holds as little as does the equilibrium ratio for the monobasic acids.