Free energies (ΔGXXXt) and entropies (ΔSXXXt) of transfer of o-, m-, and p-aminobenzoic acids from water to water-acetone mixtures have been determined from solubility measurements at five temperatures (20–40 ° C). It is found that the specific solute-solvent interactions through dispersion forces play a major role on the nature of ΔGXXXt-composition profiles in the region of water-rich composition. However, in higher acetone concentration the hydrogen bonding interactions between the solvent molecules and the aminobenzoic acids as well as between the solvent molecules themselves were also considered. All these interactions have been proposed to interpret the ΔSXXXt-composition profiles and are discussed. |
