This paper reports a comprehensive thermodynamic treatment of the binary system ZnSO4 H2O including solution properties and phase equilibria involving various hydrates of zinc sulfate. Published thermodynamic data of ZnSO4(aq), solubilities of the hydrates of zinc sulfate and equilibrium data of the hydration dehydration reactions have been collected and critically assessed. The more reliable solution properties were used to evaluate the parameters of an extended form of Pitzer s ion interaction model. With this model the activity coefficients and water activities of saturated ZnSO4 solutions have been calculated yielding, together with equilibrium data of hydration dehydration reactions, the thermodynamic solubility products of the three stable phases, ZnSO4 7H2O (goslarite), ZnSO4 6H2O (bianchite), ZnSO4 H2O (gunningite), and the metastable, monoclinic ZnSO4 7H2O. Using these solubility products together with the ion interaction model, the predicted solubilities are in excellent agreement with the experimental data. The complete phase diagram of the system has been established in the temperature range (266 378) K.
Compounds
#
Formula
Name
1
O4SZn
zinc sulfate
2
H2O
water
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.