Density of Vapor and Liquid Pentafluorobenzene Along the Saturation Line

Abstract

The density of vapor and liquid pentafluorobenzene along the liquid-vapor coexistence curve has been studied by a gamma-ray attenuation technique over the temperature range from 293.5 K to 530.9 K. According to measurements, the coordinates of the critical point are T C = (531.04 ± 0.05) K and ρ C = (518.8 ± 2) kg·m −3 . The critical exponent β of the coexistence curve equals 0.345 ± 0.005. The results of our measurements were compared with data available in the literature. The height dependence of the density of a two-phase sample was investigated in relation to the temperature and time. These experiments made it possible to determine the isothermal compressibility of liquid and vapor phases near the critical point.