EN
Perturbation solution of the Boltzmann equation for a dilute gas with a chemical reaction A + A → B + B is presented. Analytical results for the nonequilibrium effects on the rate of chemical reaction are obtained for the line-of-centers model. It is shown that taking into account the energy transfer from reagents A to products B permits to get new results. The nonequilibrium corrections obtained from these results are much larger than those obtained with neglecting this energy transfer. These results are verified by a comparison with the numerical results obtained from the modified Nanbu-Babovsky Monte Carlo computer simulations.