Nonequilibrium Contribution to the Rate of Reaction. III. Isothermal Multicomponent Systems

The nonequilibrium contribution to the reaction rate of an isothermal multicomponent system is obtained by solution of the appropriate Chapman–Enskog equation; the system is composed of reactive species in contact with a heat bath of inert atoms M. It is found that the perturbation of the velocity distribution functions is determined by the extent of the departure of the reactive collision frequency $R^{\text{(0)}}({{c}}_{\gamma })$ for each reactive component $\gamma$ from ${\mathrm{R̄}}^{\text{(0)}}({{c}}_{\mathrm{ggr}})$ , the collision frequency that leaves the distribution function unaltered by reaction; the function ${\mathrm{R̄}}^{\text{(0)}}({{c}}_{\gamma })$ obtained for an isothermal systems is different from that introduced previously for an isolated system. An illustrative application is made to a model system corresponding to the H₂+Cl⇆HCl+H reaction without internal degrees of freedom; the deviation of the rate coefficient ratio ${\mathrm{(k}}_f{\mathrm{\hspace{0.17em}/\hspace{0.17em}k}}_r$ from the equilibrium value ${\mathrm{(k}}_f^{\text{(0)}}{\mathrm{\hspace{0.17em}/\hspace{0.17em}k}}_r^{\text{(0)}})$ is a few percent.