Determination and correlation of solubility and solution thermodynamics of saccharin in different pure solvents

The solubility of saccharin in seven pure solvents, including methanol, ethanol, n -propanol, isopropanol, isobutanol, ethyl acetate and acetone, was determined from 278.15 K to 323.15 K by using a gravimetric method at atmospheric pressure. The solubility of saccharin is positively related to temperature in all selected solvents. The cooperation effect between polarity and interaction bonding was revealed by the molecular simulation study to give the explanation for the sequence of solubility in various solvents. Besides, the experimental solubility data was correlated by the modified Apelblat equation, λh equation, Wilson model and NRTL model. The results indicate that all the models could give satisfactory correlation results, whereas the modified Apelblat model shows the best fitting result. Furthermore, the thermodynamic properties of the dissolution process of saccharin in the appointed solvents, including the Gibbs energy, enthalpy and entropy of dissolution, were also calculated and discussed according to the Wilson model and the result turns out that the dissolution process of saccharin is endothermic.