Solubility of Benzoin in Six Monosolvents and in Some Binary Solvent Mixtures at Various Temperatures

The solubility of benzoin in monosolvents (acetone, ethyl acetate, methanol, ethanol, 1-propanol, and 1-butanol) and binary solvent mixtures (ethyl acetate + methanol, ethyl acetate + ethanol) was measured using UV–vis spectroscopy at temperatures ranging from 283.15 K to 323.15 K. It can be seen from the data that the solubility of benzoin increases expectedly as temperature increases in a given solvent or solvent mixture, the solubility in acetone is maximum among six monosolvents which could be well explained by the existence of strong H-bonds, rather than the “like dissolves like” rule. In binary solvent mixtures, the solubility reaches maximum when the mole fraction of methanol is 0.1 in ethyl acetate + methanol mixed solvents, while the maximum exhibits at 0.2 of mole fraction of ethanol in ethyl acetate + ethanol. The solubility parameter was interpreted as the cosolvency of benzoin solubility in binary solvent mixtures. The solubility data were correlated by modified Apelbalt equation, CNIBS/R-K equation, λh equation, Jouyban–Acree model, and Van’t–JA equation. Mixing thermodynamic properties were further calculated and discussed regarding their roles in dissolution and solubility.