Some Remarks on Two-Step Exothermic Reactions with Arrhenius Kinetics and Reactants Consumption

Abstract

Many reactions that are written as a single reaction equation in actual fact consist of a series of elementary steps. Even though a balanced chemical equation may give the ultimate result of a reaction, what actually happens in the reaction may take place in several steps. A chemical equation does not tell us how reactants become products. Knowledge about this process will become extremely important as we learn more about the theory of chemical reaction rates. This paper presents an analytical method for describing two-step exothermic reactions with Arrhenius kinetics and reactants consumption. We assume that the reaction is not stirred, that is, change depends on space variable and examines the properties of the solution of the model. We solve the equations using parameter-expanding method and eigenfunctions expansion technique. The results obtained revealed that the temperature of the medium, for a non-stirred reaction, is symmetric and monotonically increasing. Also, the temperature of the medium increases and reaches steady state as activation energies ratio increases, for a well-stirred reaction.