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, λh 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 λh equation model is the most suitable for description of the solid–liquid equilibrium containing GA. Furthermore, the standard molar Gibbs energy ΔsolG⊖ and standard molar enthalpy of dissolution ΔsolH⊖ of GA were estimated.