Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The solubility of 2,4-dinitroaniline in nine organic solvents of methanol, ethanol, acetone, acetonitrile, npropanol, toluene, isopropanol, ethyl acetate and 1-butanol was determined experimentally by using the isothermal saturation method over a temperature range from (278.15 to 318.15) K under 101.1 kPa. For the temperature range studied, the solubility of 2,4-dinitroaniline in the solvents increased with a rise of temperature. At a specific temperature, the mole fraction solubility is lowest in toluene, and largest in acetone. The solubility order of 2,4-dinitroaniline is acetone greater than ethyl acetate greater than acetonitrile greater than 1- butanol greater than ethanol greater than methanol greater than (n-propanol, isopropanol) greater than toluene. The modified Apelblat equation, kh equation, Wilson model and NRTL model were employed to correlate the solubility of 2,4- dinitroaniline in the solvents studied. The maximum values of root-mean-square deviation (RMSD) and relative average deviation (RAD) were 3.76 10 4 and 1.44%, respectively. The values of RAD obtained with the modified Apelblat equation were smaller than those with the other three models for a certain solvent. Generally, the four thermodynamic models were all acceptable for the systems of 2,4- dinitroaniline in these solvents. Furthermore, the mixing Gibbs energy, mixing enthalpy, mixing entropy, activity coefficient at infinitesimal concentration (c1 1 ) and reduced excess enthalpy (HE;1 1 ) were computed. The solution process of 2,4-dinitroaniline was spontaneous and endothermic in the solvents. The solubility determined and thermodynamic studies would be very helpful for optimizing the purification process of 2,4-dinitroaniline.