Solubility and thermodynamic properties of 2-naphthoxyacetic acid in twelve mono-solvents

The solubility of 2-naphthoxyacetic acid in methanol, ethanol, n -propanol, i-propanol, i-butanol, n -pentanol, methyl acetate, ethyl acetate, n -propyl acetate, i-propyl acetate, acetonitrile, and acetone was determined with the gravimetric method under the barometric pressure in the temperature range of 278.15 K to 323.15 K. The experimental results indicate that the solubility of 2-naphthoxyacetic acid in the twelve solvents was positively related to temperature over the whole range of temperature studied. Six mathematical models were used to fit the experimental results, including modified Apelblat equation, UNIQUAC model, λh equation, NRTL model, Two-Suffix Margules model and Jouyban model. The best correlation results were shown using the modified Apelblat model. The Hansen Solubility Parameter (HSP) was used to discuss the order of solubility of 2- naphthoxyacetic acid in the studied solvents. In addition, the thermodynamic properties during the dissolution of 2-naphthoxyacetic acid were analyzed and discussed according to the Van't Hoff equation.