Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

The excess molar volumes VEm and excess molar enthalpies HEm have been measured for the binary mixtures of {1,2-dichloropropane + methyl ethanoate, or + methyl propanoate, or + methyl butanoate} using a densimeter and an isothermal microcalorimeter, respectively, at T = 298.15 K and P = 1 atm. The HEm values of all binary mixtures are negative while VEm values are positive over the whole composition range. Both VEm and HEm values decrease with an increase of molecular weight of methyl esters. The maximum negative values of HEm for these binary systems were observed at x1 = 0.45-0.51. But, the maximum positive values of VEm lie at 0.49-0.65 mole fraction of 1,2-dichloropropane. The experimental results are discussed in terms of intermolecular interactions, particularly the self-association by dipole-dipole attraction between like and unlike molecules and formation of empty space around the molecules in the mixtures. The experimental data were correlated by three local-composition models (Wilson, NRTL, and UNIQUAC). Out of three models, NRTL equation provides the most appropriate correlating results except the binary system containing methyl butanoate.