Effect of Temperature and Evaluation of Thermodynamic Parameters for Ag(I) Catalyzed Oxidation of Tris (2, 2´-bipyridine)Fe(II)complex ion by peroxodisulfate

Abstract

Ag(I) catalyzed oxidation of tris(2,2’-bipyridine)Fe(II) complex ion by peroxodisulfate has been undertaken at different temperatures (20°C-40°C). Redox reaction was investigated at different temperatures to evaluate the thermodynamic parameters of activation ΔH # , ΔS # and ΔG # . The value of energy of activation (Ea) of the redox reaction was estimated from Arrhenius plot and found to be 18.316±0.21 kJ/mol. The values of thermodynamic parameters of activation such as enthalpy of activation (ΔH # ) and entropy of activation (ΔS # ) were consequently evaluated from Eyring plot. The Gibbs energy of activation (ΔG # ) was calculated by employing equation, ΔG # = ΔH # − TΔS # . These values have been estimated with standard deviation to be as ∆H # =15.92±0.42 kJ/mol, and ∆S # = -73.85±1.97 J/mol.K and ΔG # = 37.93± 0.78 kJ/mol at 298K. The positive values of ∆H # and ∆G # recommend the redox reaction to be an endothermic reaction.