Ion exchanger as canonical assembly: Calculation of the phase composition in multicomponent systems

Ion exchanger is considered as the phase space being Gibbs canonical assembly. It is shown, that the canonical energy distribution results in a linear dependence of the differential free energy of ion exchange on the molar fraction of counterions in the ion exchanger phase in binary or multicomponent systems. A method for calculating of the phase composition of an ion exchanger at equilibrium with a multicomponent solution of electrolytes was proposed and tested for many experimental model systems.