Measurements of HmE and VmE for {xC4H10 + (1 − x)SF6} in the supercritical region at the pressure 8.00 MPa

Measurements of the excess molar enthalpy HmE and the excess molar volume VmE of {xC4H10)+(1−x)SF6} made in the supercritical region at the pressure p=8.00 MPa and seven temperatures over the range 311.25–425.75 K are reported. The measurements extend the range of similar measurements made at the pressure 6.00 MPa reported recently. The measurements were made using a flow mixing calorimeter followed by a vibrating tube densimeter. The results are compared with the Patel–Teja (PT) equation-of-state with parameters determined by solving a cubic equation as they recommend, and also with parameters determined by the method suggested by Valderrama–Cisternas (VC) who proposed equations in which the parameters are a function of the critical compressibility factor Zc. The overall fit to the HmE and VmE measurements obtained using the Valderrama and Cisternas equation is found to be better than that obtained using the parameters obtained by the method suggested by Patel and Teja.