Thermodynamics of liquid mixtures of xenon and carbon tetrafluoride

Abstract

The total vapour pressure, excess enthalpy and excess volume of the system carbon tetrafluoride + xenon have been measured as a function of composition; the vapour pressure and excess volume measurements are at 159.01 K (the triple-point of HCl) and those for the excess enthalpy are at 163.01 K. The vapour pressure results have been used to estimate the excess Gibbs energy. The mixture exhibits a positive azeotrope at a xenon mole fraction of ca. 0.19. The experimental results are compared with values calculated from perturbation theory for non-spherical molecules, using an intermolecular potential model that includes octopole–octopole and anisotropic dispersion and overlap terms. Agreement is good for both the pure fluid and mixture properties.