ELECTROCHEMICAL REDUCTION OF CADMIUM(II) COMPLEXES WITH SOME SULPHONAMIDES AND CEPHALOTHIN ON DROPPING MERCURY ELECTRODE

摘要

Polarographic and thermodynamic aspects concerning the behaviour of Cd(II) complexes with some sulphonamides and cephalothin in aqueous solutions of pH = 7.30 ± 0.01 in the presence of 1.0 M KNO3 at 25°C have been investigated. The nature of electrode processes was reversible and diffusion-controlled. The stability constants of complexes and the effect of temperature on it have been determined by determining thermodynamic parameters such as free energy change (ΔG),enthalpy change (ΔH) and entropy change (ΔS). The formation of metal complexes has been found to be spontaneous,exothermic and entropically unfavourable at higher temperature. The stoichiometry of these complexes was determined by the Schaap and McMaster method and found to be 1:1:1,1:2:1 and 1:1:2 n (metal):n (sulphonamide):" (cephalothin) complexes.