ON THE VISCOSITY OF NONDEGENERATE REACTING GASES

The viscosity of a nondegenerate molecular gas A, in equilibrium with its dissociation products B and C (having comparable masses) is considered. In contrast with the usual van der Waals corrections to Maxwell's formula, a new term is found, which decreases with pressure and increases with temperature. The prevalence of these effects on van der Waals corrections and its experimental observability are studied. It is shown that alkaline molecules, at pressures of order 10(-2) Torr, and temperatures below 10(3) K, should be good candidates to display the effect of a gaseous viscosity decreasing with the square root of the pressure.