Pressure and temperature dependence of the self-diffusion of carbon tetrachloride

Abstract

A modified diaphragm cell method has been used to measure the self-diffusion coefficient of carbon tetrachloride at 283, 298, 313 and 328 K over the pressure ranges 1–769, 1–1216, 1–1469 and 1–1475 bar, respectively. These results are compared with less extensive data from other methods and used with data reported elsewhere for benzene and cyclohexane to test some current theories of transport. In a test of the Stokes–Einstein relation best agreement between theory and experiment was obtained for the pseudo-spherical molecules of carbon tetrachloride for which constancy of (Dη/T) is maintained over the full range of temperature and pressure. A comparison of the present results with literature values calculated from molecular dynamics of hard spheres shows that the density dependence is not the same and the two cannot be reconciled by a temperature dependent hard sphere diameter. Internal pressures calculated from the data are not dependent on a model of the liquid and are in reasonable agreement with directly determined values.