Nonequilibrium effects on the rate of bimolecular chemical reaction in a dilute gas

Abstract

The perturbation solution of the Boltzmann equation in a dilute gas shows that the rate constant of chemical reaction A+ A ⇄ B+ B is diminished due to nonequilibrium effects. For the line-of-centers model, the relative decrease η of the reaction rate can reach even nearly 45% (for a small reduced threshold energy ε * and a large molar fraction x B). For slow reactions this method is valid and η does not depend on x B. The appropriate equilibrium expressions for reaction rate (with: (a) the temperature of the system T, (b) the nonequilibrium Shizgal–Karplus temperatures T A and T B) are used for this analysis.