Study of Complex Formation Between Malonic Acid and Cd(II) Ion in Aqueous and Non-Aqueous Solvents using Polarography

Abstract

Studies of Cd(II) complexes with malonic acid have been carried out by polarographic method in aqueous and non-aqueous media (30 % DMSO, 30 % DMF, 30 % ethanol) under varying temperatures, at 303 and 308 K in presence of KCl as a supporting electrolyte. The reduction of Cd(II)was found to be reversible in aqueous and non-aqueous medium for malonic acid ligand and have shown the formation of 1:1, 1:2 and 1:3 complexes. DeFord and Hume's method as modified by Irving has been applied for the determination of composition and stability constant of the complexes species. The changes in thermodynamic parameters DHº, DGº and DSº accompanying complexation have been evaluated. The mathematical Mihailov's method has also been applied for the comparison of stability constants values.