Abstrato

Calculation of Thermodynamic Parameters of Copper Complexes Using Shedlovsky Technique

N Mohondas Singh, Lanuwapang Jamir, and Lalrosanga

Our work has done to measure conductivity of copper (II) ion complexes in aqueous medium at different temperatures ranging from 283 to 303K. The limiting molar conductance values have been calculated at molar concentrations varying from 1.1 to 0.569 x 10-3 M. The conductance data in all the cases have been analyzed by Shedlovsky Technique to obtain limiting molar conductance (Λ0) and ion association constant (KA) values for the electrolytes. It is observed that the limiting equivalent conductance increased linearly with the increased in temperature and the association constant values decreased with rise in temperature. The limiting molar conductance and ion association constant values for bis-1-amidino-O-methylurea copper (II) bromide are found to be higher than those in bis-1-amidino-O-methylurea copper (II) iodide. Thermodynamic parameters (i.e., ΔG0, ΔH0, ΔS0) are estimated from the temperature dependence of the ion association constant. The selected two metal complexes show ion-pair association within experimentally different temperatures which are supported by the negative value of ΔG0. The positive values of ΔS0 and positive values of ΔH0 indicate that the ion association process occurred spontaneously as well as endothermic at all respective temperatures. The association constant values for both complexes are determined and found in the order bis-1-amidino-O-methylurea copper (II) bromide > bis-1-amidino-O-methylurea copper (II) iodide.