Kinetics of ion exchange of some complex cations on chromium ferrocyanide gel

Abstract

The parameters effective diffusion coefficients, activation energies, and entropies of activation are reported for the exchange of the ammine-complex cations of cobalt, viz. [Co(NH 3 ) 6 ] 3+ and[Co(en) 3 ] 3+ (en = enthylenediamine) on chromium ferrocyanide gel in the H form. The values of these constants throw significant light on the possible structural changes in the exchanger framework caused by the introduction of these large size complex cations. Kinetic measurements have been made as the function of particle size of the exchanger, temperature, and solution concentration of the exchanging ions. The slow step governing the rate of exchange is diffusion of ions through the exchanger particles.