Abstract

Evaluation of Thermodynamic Activation Parameters of Cobalt Orthovanadate Membrane

Author(s): Badrul Islam and Sanadelaslam Elhaddad

In the present work, the preparation of parchment supported cobalt orthovanadate membrane has been described. The ion transport through the membrane has been computed using the Kittelberger's equation based on the simple laws of electrolysis. The assembly used provides the data for various membrane parameters like membrane resistance, membrane potential and the diffusion rate of ions within a very short period, i.e. within two – three minutes, with reasonable accuracy. By applying the theory of absolute reaction rate, various thermodynamic parameters, namely, enthalpy of activation ΔH≠, energy of activation ΔF≠, and entropy of activation ΔS≠ were evaluated. The ΔS≠ values were found to be negative, indicating that diffusion takes place with partial immobilization in the membrane phase. A formal relation between ΔFhydration, ΔHhydration and ΔShydration of cations with corresponding values of ΔF≠, ΔH≠ and ΔS≠ for diffusion was also worked out.