Thermodynamic properties on quaternary aqueous solutions of chlorides charge-type 1-1*2-1*2-1: XCl + MgCl2 + CaCl2 + H2O with (X ≡ Na+; NH4+)

In this investigation, the quaternary aqueous solutions of chlorides charge-type 1-1*2-1*2-1 with a cation (Na+; NH4+; Mg2+; Ca2+) have been studied using the hygrometric method at 298.15 K. The water activities of the systems NH4Cl + MgCl2 + CaCl2 + H2O and NaCl + MgCl2 + CaCl2 + H2O are measured at total molalities from 0.60 mol kg−1 to saturation for different ionic-strength fractions NH4Cl or NaCl, y = 0.20, 0.50, 0.80, and z ratio ionic-strength for other solutes, with z = 0.20, 0.50 and 0.80 for each y. The obtained data allow the deduction of osmotic coefficients.The ionic interaction model with our approach is developed and evaluated the mixing ionic parameters φ and χ for quaternary systems. From these measurements, newly quaternary parameters φ and χ are determined and used to predict the solute activity coefficients in the mixtures. The results are compared with experimental data.