Determination of water activity, osmotic coefficient, activity coefficient, solubility, excess Gibbs energy and transfer Gibbs energy of KCl-D-sucrose-water mixture at 298.15 K

In this paper, we present the results of investigations of the KCl-D-sucrose-H2O ternary system using hygrometric method based on measurement of the relative humidity at the wide range of concentration to about saturation for both KCl and D-sucrose in different molalities of D-sucrose of (0.20, 0.50, 1.00, 2.00, 3.00, 4.00, 5.00 and 6.00) mol.kg(-1) with the molality of KCl ranged from (0.20 to 4.50) mol.kg(-1) at 298.15 K. The measured data are used to determine the water activities and osmotic coefficients. These studies are complemented using Pitzer-Simonson-Clegg model to understand different interactions involved between carbohydrates and KCl. Therefore, the water was considered as reference state in this study. Thus four mixture parameters are determined and used to predict the mean activity coefficients of KCl and D-sucrose. The solubility, excess Gibbs energy and transfer Gibbs energy are also calculated for this system. (C) 2019 Elsevier Ltd.