Self-diffusion of Co²⁺ ions in CoSO₄ in agar gel medium: Concentration dependence of obstruction effect and activation energy

Abstract

The obstruction effect and activation enerqy for the self-diffusion of Co²⁺ ions in CoSO₄ have been computed using the zone-diffusion technique in agar gel medium at five different concentrations of the electrolyte. Both parameters are found to decrease with an increase in electrolyte concentration. The decrease in obstruction effect expressed in terms of α is attributed to the competitive hydration between ions and agar molecules in a diffusion system while the decrease in activation energy is explained by considering the changes in the physical properties of the solution with concentration at microscopic level.