Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The solubility of 5-methyl-2-pyrazinecarboxylic acid (MPCA) in twelve pure solvents within the temperature range from (273.15 to 313.15) K under atmosphere pressure (101.3 kPa) was determined and correlated by the modified Apelblat equation, h equation and Wilson model. The results increased with increasing temperature, and at a certain temperature, it decreased with the following sequence: 1,4-dioxane greater than ethanol greater than n-propanol greater than 1-butanol greater than methanol greater than isopropanol greater than acetone greater than 2-butanone greater than ethyl acetate greater than water greater than acetonitrile greater than toluene. Moreover, the (KAT-LSER) method was applied to analyze the effect of the solute-solvent intermolecular interactions on the solubility in pure organic solvents. The maximum values of RAD and RMSD were no more than 1.67 s and 3.43 e10-4, respectively. Furthermore, the mixing Gibbs energy, mixing enthalpy and mixing entropy were calculated by Wilson model as well, and the values of poundsGmixG and poundsGmixH are all negative, while the AmixS are all positive, which indicate the mixing process is not only exothermic but also entropy-driving.