Prediction of vapour pressure of aqueous solutions of single and mixed electrolytes

Abstract

A simple method is proposed for estimating the vapour pressures of aqueous single electrolyte solutions at 25°C. The method is based on a single empirical parameter, K. The treatment is extended to include different temperatures as well as solutions of mixed electrolytes. The estimation of vapour pressures in mixed solutions requires knowledge of the K values of constituent electrolytes and the vapour pressure of aqueous solutions of two reference electrolytes, viz. LiBr and NH₄NO₃ at 25°C. The calculated vapour pressures of single and mixed electrolyte solutions are in agreement with experimental data within 1.6% in general.