Solubility and solution thermodynamics of hippuric acid in various solvents from 298.15Â K to 328.15Â K

The solubility of hippuric acid in methanol, ethanol, 1-propanol, 1-butanol, 1,4-dioxane, chloroform, dimethylformamide and tetrahydrofuran was measured by gravimetric method over a temperature range (298.15 to 328.15) K at atmospheric pressure. The solubility of hippuric acid is found to increase nonlinearly with temperature. Further, in alcoholic solvents, solubility is maximum in methanol and minimum in 1-butanol whereas in non alcoholic solvents, solubility is greater in dimethylformamide and minimum in chloroform. The experimental solubility data were correlated with temperature by modified Apelblat and Buchowski-Ksiazczak λh equations. The experimental data and model parameters would be useful for optimizing the process of purification. Some apparent thermodynamic parameters such as dissolution enthalpy, Gibb's free energy, and entropy of mixing have also been calculated by Van't Hoff analysis.