Molar excess heat capacities and excess volumes of 1,2-dichloroethane + cyclooctane, + mesitylene, and + tetrachloromethane

Abstract

Molar excess volumes V E at 298.15 K were obtained, as a function of mole fraction, for the three binary liquid mixtures 1,2-dichloroethane + cyclooctane, + mesitylene (1,3,5-trimethylbenzene) and + tetrachloromethane from measurements of the density with a vibrating-tube densimeter. In addition, a Picker flow calorimeter was used to determine molar excess heat capacities C p E at 298.15 K for each of these three mixtures. The excess volumes are positive in all cases, the largest value of V E being found for { xCH 2ClCH 2Cl + (1 − x) c-C 8H 16}: V max E = 1.08 cm 3 mol −1 at x = 0.493. C p E is negative for the mixtures with cyclooctane ( C p, min E = −2.20 J K −1 mol −1 at x = 0.412) and S-shaped behaviour is observed for the other two mixtures: at high mole fractions of CH 2ClCH 2Cl, C p E is negative for 1,2-dichloroethane + mesitylene and positive for 1,2-dichloroethane + tetrachloromethane.