THERMODYNAMICS OF THE PARTIALLY MISCIBLE SYSTEM ETHANOL + HEXADECANE

The following properties of ethanol + hexadecane are reported: vapour pressure at 325.25 K; enthalpy of mixing at 298.15, 308.15, 318.15, and 325.25 K; compositions of coexisting phases from 298.15 to 325.25 K; excess volumes at 298.15 and 318.15 K. From these results activity coefficients and partial enthalpies of both components are calculated. The experimental results are interpreted by a model of association of ethanol molecules into open-chain and cyclic hydrogen-bonded groups with allowance for a non-polar interaction. The activities and enthalpies are well reproduced, and phase separation is predicted, but the compositions of the conjugate phases cannot be quantitatively accounted for with the single temperature-independent non-polar interaction term which suffices for the other properties. © 1979.