Excess molar volumes and excess molar enthalpies for binary mixtures of 1,2-dichloropropane with methyl ethanoate, methyl propanoate, and methyl butanoate at T = 298.15 K

The excess molar volumes V m E and excess molar enthalpies H m E 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 H m E values of all binary mixtures are negative while V m E values are positive over the whole composition range. Both V m E and H m E values decrease with an increase of molecular weight of methyl esters. The maximum negative values of H m E for these binary systems were observed at x1 = 0.45–0.51. But, the maximum positive values of V m E 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.