Experimental Data and Thermodynamic Modelling of Gallic Acid Solubility in a Variety of Pure Solvents

The solubility of gallic acid (GA) in butan-1-ol, butan-2-ol, hexan-1-ol, 1,4-dioxane, ethyl acetate, methyl acetate and cyclohexanone from 293.15 to 318.15 K has been experimentally measured using a thermostatted reactor and UV/vis spectrophotometer analysis. The results demonstrate that the solubility of GA generally increased with the temperature and at a given temperature decreased with the increase of the carbon number of alcohols. The van't Hoff model, modified Apelblat equation, h equation and the Two Local composition models of Wilson and NRTL model were used to predict the reported solubilities, resulting in a mean relative deviation of 3.47%, 3.54%, 2.90%, 3.12% and 3.18%, respectively. The obtained data showed that the h equation model is the most suitable for description of the solid-liquid equilibrium containing GA. Furthermore, the standard molar Gibbs energy and standard molar enthalpy of dissolution of GA were estimated.