VISCOSITY OF 3 POLAR GASES

A report is presented on new, accurate measurements of the viscosity of three polar gases: nitrous oxide (N//2O), trichlorofluoromethane (CCl//3F) and chlorodifluoromethane (CHClF//2). The measurements were performed at atmospheric pressure in the temperature range 27. 5-200 degree C, and the accuracy of the reported viscosities is estimated to be one of plus or minus 0. 2%. It is shown that the results can be represented by the extended law of corresponding states developed by Kestin, Ro, and Wakeham, despite the polar nature of the gases. The scaling factors sigma and epsilon which secure the best representation of this kind are determined. That the three polar gases can be included in a correlation scheme developed originally for non-polar gases is shown to be due to the relative weakness of the dipole-dipole interaction term in their intermolecular potentials.