Kinetic and thermodynamic characteristics of the hexacyanoferrate ll/III redox system in <i>t</i>-butanoVwater mixed solvent

401-406The kinetic and thermodynamic parameters controlling the hexacyanoferrate II/III redox reaction in t-butanol/water mixtures have been derived using a gold rotating disc electrode with a standard potentiostatic technique. The effect of temperature on the current-voltage characteristics of the gold rotating disc electrode in the hexacyanoferrate redox system at different compositions of the solvent mixture has been studied and thermodynamic parameters have been evaluated. The presence of t-butanol in the solvent mixture enhances the rate of charge transfer reactions with respect to the diffusion controlled reactions. From the thermodynamic point of view, the rate of the cathodic process is independent of both the enthalpy or the entropy of the process and compensation effect is present. The anodic process obeys an entropy-controlled mechanism. Chemical potential calculations show that the concentration of the activated complex in the case of the anodic process is lower than that corresponding to the cathodic process