MOLAR EXCESS HEAT-CAPACITIES AND EXCESS VOLUMES OF 1,2-DICHLOROETHANE + CYCLOOCTANE, + MESITYLENE, AND + TETRACHLOROMETHANE

Molar excess volumes VE 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 CpE at 298.15 K for each of these three mixtures. The excess volumes are positive in all cases, the largest value of VE being found for {xCH2ClCH2Cl + (1 - x)c-C8H16}: VmaxE = 1.08 cm3 mol-1 at x = 0.493. CpE is negative for the mixtures with cyclooctane (Cp, minE = -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 CH2ClCH2Cl, CpE is negative for 1,2-dichloroethane + mesitylene and positive for 1,2-dichloroethane + tetrachloromethane. © 1979.