Measurements of Saturation Densities in the Critical Region of Pentafluoroethyl Methyl Ether (245cbEβγ)

Abstract

We have measured 10 saturated-vapor densities and 13 saturated-liquid densities in the critical region of pentafluoroethyl methyl ether, CF3CF2OCH3 (245cbEβγ), based on the direct visual observation of the meniscus disappearance in an optical cell. The critical temperature and density have been determined by taking into consideration the meniscus disappearing level of the sample within the optical cell as well as the intensity of the critical opalescence. The experimental uncertainties of saturation temperature and density measurements were estimated to be within ±12 mK and ±(0.5 to 4.0) kg·m-3, while those of the critical temperature and density values determined are to be within ±17 mK and ±3 kg·m-3, respectively. We have also determined the critical exponent, β, and the critical amplitude, B, on the basis of the vapor−liquid coexistence curve correlation developed.