Thermodynamic properties of binary liquid mixtures containing fluoroalcohols.

A detailed investigation into the thermodynamic properties of pure fluoroalcohols and binary mixtures containing fluoroalcohols is described. A batch calorimeter was used to measure excess enthalpies over the complete composition range and enthalpies of solution were obtained using an L.K.B. 8700 calorimeter. The excess volumes were determined using both batch and dilution dilatometers. Vapour-liquid equilibrium diagrams for binary mixtures have been determined from vapour pressure measurements using a static vapour pressure apparatus. Enthalpies of vaporisation of the fluoroalcohols were determined from the variation of the vapour pressure with temperature. Solid-liquid equilibrium phase diagrams have been determined using a simple freezing point cell, and liquid-liquid measurements obtained using a synthetic method. A new isothermal dilution calorimeter is also described. Unlike the batch calorimeter it allows a wide composition range to be studied from a single loading. The results for the test systems benzene + cyclo- hexane and benzene + tetrachloromethane obtained with this calorimeter are presented. The results obtained are in excellent agreement with those obtained by other workers.