Solubility and Thermodynamic Modeling of 5-Nitrofurazone in Pure Solvents and Binary Solvent Mixtures

Abstract

In this work, the solubility of 5-nitrofurazone (Form α) in 10 pure solvents (water, methanol, ethanol, acetonitrile, ethyl acetate, n-propanol, isopropanol, acetone, formamide, N,N-dimethylformamide) and two binary mixed solvents (N,N-dimethylformamide + water, N,N-dimethylformamide + acetonitrile) were measured by ultraviolet–visible spectrophotometry from 278.15 to 313.15 K. The experimental results showed that the solubility of 5-nitrofurazone (Form α) in all pure solvents and binary mixed solvents was positively correlated with temperature. Additionally, the modified Apelblat equation, the λh equation, and the nonrandom two-liquid (NRTL) model were used to correlate the experimental solubility results. The results showed that all of these models could correlate the experimental data well, and the modified Apelblat equation provided the best fitting results. Finally, the mixing and dissolution thermodynamic properties of 5-nitrofurazone (Form α) in 10 pure solvents and two binary solvents, including enthalpy, entropy, and Gibbs energy, were calculated by experimental results and the NRTL model.