Solubility measurement and thermodynamic functions of 3-nitrobenzaldehyde in different solvents at elevated temperatures

Abstract

The solubility was measured for 3-nitrobenzaldehyde in methanol, ethanol, isopropanol, n-butanol, acetonitrile, acetone, ethyl acetate, toluene, N,N-dimethylformamide, acetic acid, cyclohexane and n-propanol by using a high-performance liquid chromatography analysis under pressure of 101.2kPa. The temperatures of solubility determination were from (273.15 to 303.15)K. The mole fraction solubility of 3-nitrobenzaldehyde increased with the increase in temperature, and obeyed the following order from high to low in different solvents: N,N-dimethylformamide>(acetone, acetonitrile)>ethyl acetate>toluene>methanol>acetic acid>ethanol>n-propanol>n-butanol>isopropanol>cyclohexane. Four models, modified Apelblat equation, λh equation, Wilson model and NRTL model were employed to correlate the experimental mole fraction solubility. The largest root-mean-square deviation (RMSD) was 6.98×10−3, and the largest relative average deviation (RAD) was 1.93% for each set of solubility results. On the whole, the calculated solubility values were in good agreement with the experimental results for the four selected models, and the NRTL provided the best results. Moreover, the mixing Gibbs energy, mixing enthalpy, mixing entropy, activity coefficient at infinitesimal concentration (γ1∞) and reduced excess enthalpy (H1E,∞) were computed based on the NRTL model. The experimental solubility, thermodynamic models and thermodynamic properties are very important in the purification process of isomeric mixtures of nitrobenzaldehydes.