Abstract

The solubility of 2-ethoxy-1-naphthoic acid was determined experimentally in 12 pure solvents (methanol, ethanol, n-propanol, i-propanol, i-butanol, n-pentanol, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, acetone and acetonitrile) using the gravimetric method in the temperature range of 278.15 K to 323.15 K at atmospheric pressure. The study found that solubility increased with temperature, with acetone exhibiting the highest solubility and acetonitrile the lowest at 298.15 K. Furthermore, the influence of solvent properties on solubility, such as polarity and dielectric constant, was analyzed, showing a positive correlation. Mathematical models (including modified Apelblat, NRTL, Margules, UNIQUAC and λh models) were employed to analyze the dissolution process, with the modified Apelblat model providing the best fit to the experimental data. Additionally, thermodynamic properties of the dissolution process were obtained using the Van't Hoff equation, indicating an entropy-increasing process with heat absorption. Overall, this study elucidates the solubility behavior and related mechanisms of 2-ethoxy-1-naphthoic acid in various solvents, providing theoretical support for its application in solution systems.