Determination and correlation of solubility and solution thermodynamics of 4-aminobenzenesulfonamide in five binary solvent mixtures from 278.15 to 318.15 K

Abstract

The solubility of 4-aminobenzenesulfonamide in five binary solvent systems, including methanol + toluene, ethanol + toluene, methanol + chloroform, ethanol + chloroform and methanol + ethanol under ambient pressure was measured using a gravimetric method at temperatures ranging from 278.15 to 318.15 K. The results illustrated that solubility of 4-aminobenzenesulfonamide in pure methanol is highest whereas that in chloroform is lowest in all tested solvents and solvent mixtures. In methanol containing mixed solvent systems, the solubility of 4-aminobenzenesulfonamide is just increased with increasing mass fraction of methanol whereas in ethanol containing systems the solubility of solute increased with increasing mass fraction of ethanol. The mole fraction solubility increases with increase in temperature in all pure and binary solvent systems. Five thermodynamic models, including modified Apelblat, Jouyban-Acree, van't Hoff- Jouyban-Acree, Apelblat- Jouyban-Acree and Wilson equations are selected to correlate the experimental solubility data in mixed solvents whereas modified Apelblat, van't Hoff and λh models used for pure solvents. All the results from fitted values indicate that those thermodynamic models were satisfactory agreement with experimental solubility results. The mixing thermodynamic properties of 4-aminobenzenesulfonamide in five binary solvents including Gibbs energy of mixing, enthalpy of mixing and entropy of mixing, reduced excess enthalpy (H1E, ∞ ), activity coefficients γ1and γ1∞ were calculated based on the Wilson model and thermodynamic relations.