Quantitative characteristics of hydration in solutions of sodium sulfate and sodium chloride at 278.15–323.15 K

The solvation parameters of aqueous solutions of sodium chloride and sodium sulfate were studied on the basis of published density and ultrasound velocity data. Correct thermodynamic relations for temperature variation from 278.15 to 323.15 were used to determine quantitative parameters of solvation, in particular, the hydration numbers h, the molar adiabatic compressibility of hydrate structures β _h V _h , the volume V _1h and compressibility β _1h of water in the hydration shells of ions, and others. h and β _h V _h do not depend on temperature in the range of parameters studied, and electrostriction compression about the ions has a more pronounced effect on the structure than mere pressure change.