Dipole-dipole interaction and viscosity of polar gases

The viscosity of the polar gases NH 3 , SO 2 , CH 3 Cl and H 2 S has been measured in the temperature range from -50 degrees C to 35 degrees C by the oscillating-disk method. The data have been utilized to test the validity of the various approximations used to represent the dipole-dipole interaction term in the intermolecular potential for polar molecules. The results show that viscosity of these polar gases can be represented reasonably well by effectively spherically symmetric potential functions.