Determination and correlation of solubility and dissolution thermodynamics of m-toluic acid and isophthalic acid in binary (water plus ethanoic acid) solvent mixtures

The solubilities of m-toluic acid (m-TA) from 313.2 to 383.2 K, as well as those of isophthalic acid (IPA) from 373.2 to 463.2 K in water, ethanoic acid, and their mixtures were measured by the steady-state method. The modified Apelblat equation was used to correlate the experimental solubilities of m-TA, as well as those of IPA. The F-test shows that the modified Apelblat equation is suitable to model the solubilities of m-TA and IPA, respectively. Based on the determined solubility data, the thermodynamic parameters including the apparent molar enthalpy and entropy concerning solute dissolution were further calculated. We hope that the solubility data and related thermodynamic parameters can provide valuable insights into the design and optimization of the industrial manufacture of IPA.