Solubility and Solution Thermodynamics of 3-Nitrophthalonitrile in 12 Neat Solvents at Temperatures from 278.15 to 323.15 K

In this investigation, using the static equilibrium method, the solubility of 3-nitrophthalonitrile in 12 pure solvents, namely, n -propanol, methanol, ethanol, isopropanol, ethylene glycol (EG), acetone, toluene, N -methyl-pyrrolidone (NMP), n -butanol, ethyl acetate, isobutanol, and water, was investigated through experiment over a temperature range of 278.15–323.15 K under ambient pressure p = 101.2 kPa. The mole fraction solubility of 3-nitrophthalonitrile in above solvents increased as the temperature increased and had the following order in different solvents: NMP > acetone > ethyl acetate > EG > methanol > ethanol > toluene > n -propanol > isopropanol > n -butanol > isobutanol > water. The solubility was correlated using the Wilson model, λ h equation, modified Apelblat equation, and NRTL model. Results indicated that the maximum values of root-mean-square deviation and relative average deviation were 11.75 × 10 –4 and 9.26 × 10 –2, respectively. The relative average deviation values achieved with the modified Apelblat equation were lower than those with the other equations for a given solvent. Additionally, the mixing properties and reduced excess enthalpy and activity coefficient under infinitesimal concentration were derived.