Method for Calculating the Density of Mixed Solutions of Strong Electrolytes

A method is proposed for calculating the density of solutions of strong electrolytes using the product of the apparent molar volume of the electrolyte by its molality. This method can be used to calculate the density of mixed electrolyte solutions, for example, when determining the activity by the Gibbs–Duhem equation. According to the literature data on the densities of solutions at 20°C, the apparent molar volumes of NaCl, NaNO3, KCl, KNO3, and SrCl2 are calculated and the high accuracy of calculations is demonstrated.