CROSSOVER LEUNG-GRIFFITHS MODEL AND THE PHASE-BEHAVIOR OF DILUTE AQUEOUS IONIC-SOLUTIONS

A new parametric crossover model for the phase behavior of a binary mi xture is presented that corresponds to the Leung-Griffiths model in th e critical region and is transformed into the regular classical expans ion far away from the critical point. The model is optimized to, and l eads to excellent agreement with, isothermal vapor-liquid equilibrium data for dilute aqueous solutions of sodium chloride by Bischoff and c o-workers. It then accurately predicts constant-composition phase equi librium loci as measured by independent workers. This crossover model is therefore capable of representing the thermodynamic surface of ioni c solutions in a large range of temperatures and densities around the critical points of vapor-liquid equilibrium.