Gas-phase PVT properties of 1,1,1,2,3,3-Hexafluoropropane

We have measured tile gas-phase P I,ʹT properties of I.l.l.2.3.3-hexalluoropropane (R-236eal. which is considered to be a promising candidate for the replacement of 1.2-dichlorotetrafluoroethane (R-114). The measurements have been performed with a Burnett apparatus over a temperature range of 340 390 K and at pressures of 0.10 2.11 MPa. The experimental uncertainties of the measurements were estimated to be within +0.5 kPa in pressure. _+8 mK in temperature, and _+_0.15" o in density. A truncated virial equation of state was developed to represent the P IʹT data and the second virial coell]cients were also derived. Tile saturated vapor densities were also calculated by extrapolating the gas-phase isothernls to the vapor pressures. The critical density estimated from the rectilinear diameter was compared with the experimental value. The purity of the R-236ea sample used in the present measttrements was 99.9 tool %.