Measurement and Correlation of the Solubility of Vanillic Acid in Eight Pure and Water + Ethanol Mixed Solvents at Temperatures from (293.15 to 323.15) K

The solubility of vanillic acid in eight pure solvents, including ethanol, 1-propanol, 2-propanol, n-butanol, isobutanol, acetone, methyl acetate, water, and binary mixtures of water + ethanol have been measured at (293.15 to 323.15) K and atmospheric pressure by using a gravimetric method. The experimental solubility in the pure solvents was correlated by the modified Apelblat equation, van’t Hoff equation, λh equation, nonrandom two-liquid (NRTL) equation, universal quasichemical (UNIQUAC) equation, and Wilson equation. The solubility in the binary mixed solvents was correlated by the modified Apelblat equation and the Jouyban–Acree equation. The correlated values based on all the selected equations showed good agreement with the experimental values, and the correlated data of the modified Apelblat equation show the best agreement with the experimental data.