The Mean activity coefficients of KCl were determined in ethylene glycol-water mixed solvents, in the range of (10. 20, 30, and 40) % ethylene glycol, from the electromotive. force (EM F) data at (278.15, 288 15, 298.15. and 308 15) K The Pitzer and extended Debye-Huckel equations were used to describe the nonideal behavior of the electrolyte. and the corresponding activity and osmotic coefficients were determined Moreover. the standard Gibbs energy of transference of KCl-ethylene glycol-water was evaluated.