PREDICTION OF SALT EFFECT ON VAPOR-LIQUID -EQUILIBRIUM IN ETHANOL-WATER SYSTEM BY SCALED PARTICLE THEORY

The salt effect parameters(from Furter's equation) of three electrolyt es (NaCl, NaBr, KCI) for various ethanol-water mixtures were determine d by vapor-liquid equilibrium experiments. A calculation method of thi s parameter(K) by the scaled particle theory was suggested. The term o f hard sphere interactions was calculated by using Masterton-Lee's equ ation, and that of soft sphere interactions was treated by using Y. Hu 's radial distribution function method, i.e. taking the first coordina tion shell as in order, and out of the shell as random mixing. The int eractions between the charge of ions and dipole or induced dipole of t he central molecule were considered effectively within the limits of t he first coordination shell, and the ions out of the shell were regard ed as L-J molecules. In this paper a correlation equation for the loca ted dielectrical constant and liquid concentration was proposed and th e predicted results of the salt effect parameters were in agreement wi th the experiments by this equation.