• electrolyte system;
  • phase equilibrium;
  • activity coefficient;
  • mixed solvent


A generalized strong electrolyte LIQUAC model is presented to describe the vapor–liquid equilibria, osmotic coefficients, mean ion activity coefficients, and solid–liquid equilibria for the single- and mixed-solvent electrolyte systems over the entire concentration range from infinite dilution to saturated solutions. An appropriate reference state for the ions was first applied to test the capability of the model in simultaneously describing the mean ion activity coefficients and the solubility of a salt in a binary solvent mixture. The influence of salt on the vapor–liquid equilibrium behavior is predicted with the new correlated parameters. The generalized activity coefficient formulations are presented through the investigation of thermodynamic properties and phase phenomena in the single- and mixed-solvent electrolyte systems. This work is a continuous study for the LIQUAC activity coefficient model. A reliable representation of the single- and mixed-solvent salt solutions is obtained. © 2010 American Institute of Chemical Engineers AIChE J, 2011