An equation of state for electrolyte aqueous solution is developed by treating the ion-ion electrostatic and ion-solvent molecule interactions with primitive MSA and perturbation theory, respectively. The effect of the dielectric constant on the ionic chemical potential and the calculation accuracy of ionic mean activity coefficients for 2∶1 and 1∶1 type halide aqueous solution are discussed.By taking ionic Pauling diameter as ionic hard sphere diameter for anions and treating the cation hard sphere diameter as ionic strength dependent, the equation can be used to calculate ionic activity coefficients in the moderate concentration range with good accuracy.
two equations for the calculation of surface tension of pure liquids are derived based on statistical thermodyanics by expressing the intermolecular potential as lennard-Jones pair potential.This method is simple,accurate and easy to use.The calculation results for the 22 pure liquids show that these equations are superior to the empirical forula and other theoretical equations.The average relative deviations for these two equations are within 5% and 1.5% respectively.
