Thermodynamic properties of CuSO4(aq) from 268 K to 377 K and phase equilibria in the CuSO4–H2O system

Abstract

This paper reports a comprehensive thermodynamic treatment of the binary system CuSO4–H2O including solution properties and various phase equilibria. Published thermodynamic data of CuSO4(aq), solubilities of the hydrates of copper sulfate, and equilibrium data of the hydration-dehydration reactions have been collected and critically assessed. Using an internally consistent database of solution properties in the temperature range (268–377) K, the parameters of an interaction (Pitzer) model were determined. With this model activity coefficients and water activities of saturated CuSO4 solutions have been calculated yielding, together with equilibrium data of hydration–dehydration reactions, the thermodynamic solubility products of CuSO4·5H2O, CuSO4·3H2O, and CuSO4·H2O. The complete phase diagram of the system CuSO4–H2O has been established.