Effect of temperature on the solubility of 3-aminopyridine in binary ethanol + toluene solvent mixtures

The solubility of 3-aminopyridine in (ethanol + toluene) mixed solvents has been measured between 283.15 and 323.15 K at intervals of 5.00 K by a static analytical method. Nonlinear dependences were found for the variation of solubility with temperature. The nonlinear van’t Hoff equation was proposed for correlating the experimental data. The apparent molar enthalpies of 3-aminopyridine in the solvent mixtures were determined from the temperature dependence of the solubilities. The values for the apparent Gibbs energy and the apparent entropy of solution are calculated.