Solubility and dissolution thermodynamics of hexaquoiron(III)tris(p-toluenesulfonate) in (ethanol plus water) binary mixtures within 291.15-333.15 K

The solubility of hexaquoiron(III)tris(p-toluenesulfonate) [Fe(OTs)(3)center dot 6H(2)O] in (ethanol+water) mixtures with a mole fraction of 0-0.327 ethanol was measured from 291.15 to 333.15 K by using a synthetic method. The experimental results show that the solubility of Fe(OTs)(3)center dot 6H(2)O increases with an increase in temperature and an enrichment in ethanol content. The solubility data were correlated by the modified Apelblat equation, the Redlich-Kister (CNIBS/R-K) model, and the hybrid model, and the results showed that the three models agree well with experimental data. The thermodynamic properties of the dissolution process, including enthalpy, entropy, and Gibbs energy were estimated from the experimental data by the modified van't Hoff equation, indicating that the process of the dissolution of Fe(OTs)(3)center dot 6H(2)O is endothermic and spontaneous.