Solvation behaviour of cupric chloride in non-aqueous solvents

Abstract

Electromotive force measurements have been made at 303.15K on the cell Cu_xHg/CuCl₂-(<em>m</em>) (in solvent S; S=FD, W or DMF)/AgCI/Ag where FD=formamide, W=water and DMF=dimethylformamide. The data obtained suggest that while FD and W favour deposition of Cu²⁺ from the solution onto the copper amalgam electrode in the order FD > W, DMF favours dissolution of metallic copper in the concentration range 0 < <em>m</em> < 0.0056 (the effect becomes more pronounced as <em>m </em>-> 0), but it favours deposition of Cu²⁺ ions from the solution onto the copper amalgam when <em>m > </em>0.0056. This has been explained on the basis of kinetics of electrode processes. Equilibrium constants for the dissociation processes as also the respective degrees of dissociation have been obtained by iterative procedure. The standard electrode data of the above cell have also been evaluated in FD, Wand DMF and the same have been utilized to evaluate standard molar Gibbs free energy of transfer of CuCl₂ from W -> FD or DMF. The data have been considered in terms of solute-solvent interactions.