KINETICS AND MECHANISM OF ISOTOPIC EXCHANGE FOR CO(2+) ASTERISK-CO(2+) IN TIN(IV) ANTIMONATE

The rate of the isotopic exchange of cobalt ion between tin(IV) antimonate ion exchanger in the Co2+ form and aqueous solutions vas determined radiometrically. Self-diffusion coefficients for cobalt ion were measured as a function of the variable capacity for that ion in solutions of varying acidity. The effect of a heat treatment on the rate of the isotopic exchange reaction in tin(IV) antimonate was also studied. The rate was controlled by the particle diffusion of cobalt ion and increased by heating temperature and decreased with increase of ion exchange capacity. Values for the diffusion coefficents, activation energy and entropy of activation have been evaluated which give some information regarding the mechanism of ion exchange on the surface of inorganic materials.