The ternary and quaternary electrolyte systems: Activity coefficient of NaCl measured and modeled for NaCl + C2H5OH + H2O and NaCl + KCl + C2H5OH + H2O systems

This work purpose is measuring and modeling of the ternary and quaternary systems consist of NaCl and mixed NaCl+KCl electrolyte in mixed solvents with different mass fractions (x) of C2H5OH in H2O, where x = 0.10, 0.20, 0.30, 0.40, and 0.50 and in the molality range of (0.0005-3.0) mol kg(-1). Based on potentiometric measurement technique, the experimental data are obtained. A cell consists of a Na+-glass membrane and Ag/AgCl electrodes and series of electrolyte solutions, used to calculate the activity coefficients at (298.15 +/- 0.05) K. The quaternary system of mixed NaCl + KCl electrolyte in mixed C2H5OH + H2O solvents is investigated by different molal salt ratios r (r = m(NaCl)/m(KCl) = 100, 150, 200 and 250). Modeling is implemented by using particularly, the Pitzer (P) and modified Pitzer by Merida et al. (MP) equations. There is a good agreement between the results obtained from both models. The modified Pitzer approach by Merida et al. permitted the determination of various binary ion-solvent and ternary ion-ion-solvent interaction coefficients which represents complementary data to the usual Pitzer interaction parameters for modeling the named electrolyte systems. (C) 2016 Elsevier B.V. All rights reserved.