Abstract <p>The short residence time of the fuel mixture in the operating chamber of the propulsion system at supersonic flow speeds significantly complicates its ignition. One of the promising areas associated with ensuring stable ignition of fuel mixtures in a wide range of speeds is the use of nonequilibrium plasma produced, for example, by a microwave discharge. Practical implementation of this direction requires a detailed analysis of plasma–chemical reactions occurring in the fuel mixture and finding the coefficients of the corresponding reactions. To find the coefficients of chemical reactions in a mixture of propane and air, the solution of the kinetic equation for the electron energy distribution function at a specified amplitude and frequency of the external electric field has been considered. Electrons are heated by a uniform electric field, collide with the components of the mixture, and perform elastic and inelastic collisions, which are taken into account as the dependence of the reaction cross section on the kinetic energy of the electrons. The obtained results processed as dependences of chemical reaction coefficients on the parameters of the external electric field are of interest for modeling the microwave discharge plasma used to ignite the fuel mixture.</p>