Measurements, Correlations, and Estimations of the Vapor Pressures of CaCl2, MgCl2, and BaCl2 Aqueous Solutions between 298.15 K and 328.15 K

Abstract

In this study, more vapor pressures data than from literature of the aqueous bivalent electrolyte solutions of CaCl2, MgCl2, and BaCl2 were measured using the differential static method. The concentration of salts ranged from 0.1 m to 2 m and the temperature ranged from 298.15 K to 318.15 K for the CaCl2 and BaCl2 solutions and from 298.15 K to 328.15 K for the MgCl2 solution. The experimental results show that the effects of temperature and concentration on the vapor pressure of the above aqueous electrolyte solutions are similar to the general behavior of electrolyte solutions. The experimental data were fairly correlated with a proposed empirical model similar to the Patil's. This model has the advantage of fewer parameters that would reduce computation effort and time required for correlation and prediction. The vapor pressures of the present electrolyte solutions were also predicted with the two-ionic-parameter model for individual ion activity coefficients proposed by Lin and Lee. The results showed that the estimations were reasonable and further proved the advantage of this model.