Validity of macroscopic rate equations in exothermic chemical systems

Abstract
A molecular-dynamics computer experiment is set up to study the stationary properties of an exothermic gas phase chemical system. A discrepancy is observed between the results of the simulation and predictions from macroscopic chemical kinetics. The origin of this discrepancy is found to arise from the deformation of the Maxwell distribution by reactive collisions. Quantitative agreement with the corrected rate law is established.