Abstract: The reversible cell discussed in this paper consists of the copper electrode and the Ag-AgCl electrode.By the Nernst formula and the limited formula of Debye-Hückel,the measured the activity coefficients and the relative partial molar free energies of copper chloride in H₂O-DMF mixed solvent at different experimental temperatures were calculated.The behaviors of change of the activity coefficients and the relative partial molar properties of copper chloride in H₂O-DMF mixed solvent are discussed on the basis of theory of electrolytic solution.

Key words: activity coefficient, relative partial molar free energies, mixed solvent, electrode potential, DMF(N,N-dimethylformamide), CuCl₂ (copper chloride)