Solubility Measurement and Correlation for 2-Naphthaldehyde in Pure Organic Solvents and Methanol plus Ethanol Mixtures

The solubility behavior of 2-naplithaldehyde in six pure solvents (methanol, ethanol, isopropanol, n-butyl alcohol, n-heptane, and n-hexane) and binary solvent mixtures of methanol + ethanol with various concentrations were experimentally studied by the equilibrium method at temperatures ranging from (283.15 to 313.15) K and (283.15 to 308.15) K, respectively, under an atmosphere pressure of 0.1 MPa. The solubilities of 2-naphthaldehyde in the pure solvents accord with the following order: ethanol > isopropanol > n-butyl alcohol > methanol > n-heptane > n-hexane. In the mixed solvents, the solubility of 2-naphthaldehyde increases with decreasing mass fraction of methanol. All of the solubility data were correlated with the van't Hoff equation, the modified Apelblat equation, and the lambda h equation. The correlation results with the modified Apelblat equation showed better agreement with the experimental values than those with the other two models. Furthermore, the thermodynamic properties of the dissolution process of 2-naphthaldehyde were also calculated and discussed.