Thermodynamic Properties of the NaCl+H2O System. II. Thermodynamic Properties of NaCl(aq), NaCl⋅2H2(cr), and Phase Equilibria

Abstract

Equations that described the thermodynamic properties of the NaCl+H2O system were obtained from a fit to experimental results for this system. The experimental results included in the fit spanned the range of temperature of approximately 250 to 600 K and, where available, the range of pressure from the vapor pressure of the solution to 100 MPa. New equations and/or values for the following properties are given in the present work: 1) ΔfG0m and ΔfH0m, for formation from the elements, for NaCl(cr) for 298.15 K and 0.1 MPa, 2) ΔfG0m and ΔfH0m from the elements, as well as S0m and C0p,m, all for 298.15 K, 0.1MPa, for NaCl⋅2H2O(cr), 3) the change in chemical potential for both NaCl and H2O in NaCl(aq) as a function of temperature, pressure, and molality, valid from 250 to 600 K and, where available, from the vapor pressure of the solution to 100 MPa. Comparison of the accuracies of experimental methods, where possible, has also been performed.