Water Activity – Concentration Models for Solutions of Sugars, Salts and Acids

Abstract

ABSTRACT A semi‐empirical model of water activity changes due to solute concentrations increase in solutions of electrolytes and nonelectrolytes was developed based on an extension of Raoult's law. Comparisons between predicted and observed a w data for a variety of sugars, salts and acids indicated the proposed model fitted the a” data with accuracy to ±0.001 a w up to 4–14 molalities depending upon the solutes. Percent weight concentrations of some solutes for various a” values at 25°C were presented for practical applications.