Xinbao Li, Yang Cong, Cunbin Du
Oct 1, 2016
Citations
1
Influential Citations
19
Citations
Journal
The Journal of Chemical Thermodynamics
Abstract
Abstract The knowledge of solubility and solution thermodynamics for 2-methyl-4-nitroaniline in different solvents is essential for its purification and further theoretical studies. In this work, the solid-liquid equilibrium for 2-methyl-4-nitroaniline in eleven pure organic solvents (methanol, ethanol, n -propanol, isopropanol, n -butanol, toluene, ethyl acetate, acetonitrile, 2-butanone, acetone and cyclohexane) was established with the isothermal saturation method at temperatures T = (278.15–313.15) K under pressure of 101.2 kPa, and the solubility of 2-methyl-4-nitroaniline in these solvents were determined by a high-performance liquid chromatography (HPLC). In general, the mole fraction solubility obeyed the following order from high to low in different solvents: 2-butanone > acetone > ethyl acetate > acetonitrile > methanol > ethanol > n -propanol > n -butanol > isopropanol > toluene > cyclohexane. The modified Apelblat equation, λh equation, Wilson model and NRTL model were employed to correlate the measured solubility values of 2-methyl-4-nitroaniline in the selected solvents. Results show that the largest values of RAD and RMSD obtained with the four models are no greater than 0.71% and 3.27 × 10 −4 , respectively. The modified Apelblat equation provided better results than the other three models. Furthermore, the mixing properties, including Gibbs energy, mixing enthalpy, mixing entropy, activity coefficient at infinitesimal concentration ( γ 1 ∞ ) and reduced excess enthalpy ( H 1 E, ∞ ) were computed. The dissolution process of 2-methyl-4-nitroaniline is spontaneous and favourable in the selected solvents. The solubility and associated models would be very useful for optimizing the separation process of the isomeric mixtures of 2-methyl-4-nitroaniline and 2-methyl-6-nitroaniline.