Solubility of chlorinated hydrocarbons in squalane and dinonylphthalate. Part 2

Abstract

The solubility of four saturated and two unsaturated chlorinated hydrocarbons has been measured in squalane and dinonylphthalate using a McBain balance. From these measurements, the activity coefficients at infinite dilution and the partial molar excess enthalpies and entropies of solution have been calculated. Solutions in squalane show both positive and negative deviations from ideal solution behaviour with positive excess enthalpies, whilst the solutions in dinonylphthalate all show negative deviations, the excess enthalpy being zero for the saturated chloralkanes and negative for the unsaturated compounds. Infra-red studies indicate that non-central forces exist in the solutions with dinonylphthalate. The activity coefficients have been split up into the thermal(γ_t) and athermal (γ_a) contributions; for 1,1,2,2-tetrachloroethane and cis-1,2-dichloroethylene in dinonylphthalate γ_t is considerably less than one. No explanation for this can be proposed from the present study.