Ultrasonic and Thermodynamic Study on Solute-Solvent Interaction. Binary Mixtures of 1,2-Dichloroethane with Benzene, Toluene, p-Xylene and Cyclohexane

The sound velocity and density of binary mixtures of benzene, toluene, p-xylene and cyclohexane with 1,2-dichloroethane (DCE) as a common component were measured at temperature 20–40°C, and the excess molar volume and excess compressibility of these systems were calculated. They were found to be positive. The excess compressibility is independent of temperature in the DCE-benzene system. Thermodynamical properties and the nature of intermolecular interaction in the systems were discussed. It has been shown that there is a certain weak attraction between DCE and aromatic molecules, and that there is no complex formation viz., hydrogenbonding or change transfer complex. It has been proposed that the interaction between gauche form of DCE and aromatic molecules is of electrostatic nature (dipole-induced dipole or hyperpolarizability).