RAPID-DETERMINATION OF LIQUID-VAPOR EQUILIBRIA - 2,2,2-TRIFLUOROETHANOL+TETRAHYDROFURAN AT 298.15-K

An automated vapor-pressure apparatus designed in this laboratory has been used to obtain liquid-vapor equilibria for 2,2,2-trifluoroethanol + tetrahydrofuran at 298.15 K. Curves of vapor pressure against composition (liquidus and vapor lines) are inferred from pressures and total compositions, using activity-coefficient expansions consistent with the Gibbs-Duhem equation. Deviations from vapor-phase ideality have been attributed to formation of a 1-1 hydrogen-bonded complex between trifluoroethanol and tetrahydrofuran, for which an association constant of 55 dm3 mol-1 is calculated. The experimental and computational methods described can yield accurate liquid-vapor equilibrium results in a fraction of the time required for conventional recirculating-still experiments. © 1979.