@MISC{Description_1.1simple, author = {General Description and Main Concepts}, title = {1.1 SIMPLE EXAMPLE}, year = {} }

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Abstract

Graph theory has found extensive application in chemical kinetics. It is this subject that is the goal of this chapter. Let us take а simple example to illustrate the application of graph theory to derive а steady-state kinetic equation for а complex reaction. It is а typical problem for the kinetics of complex reactions. As usual it is solved as follows. Let а mechanism Ье given for а complex reaction involving the participation of observed substances, i.e. initial reactants and products as well as intermediates. In accordance with the mechanism based оп а fun-damental law of chemical kinetics, the law of mass action, we obtain а set of differential equations accounting for the kinetics of variable inter-mediates. Assuming that the known principle of quasi-steady-state con-centrations is valid, we go from the above set of differential to that of algebraic equations whose solution provides steady-state concentrations for intermediates. Knowing these values, we сап readily obtain а general ех pression for а steady-state reaction rate as а function of the substance concentrations and temperature. The most cumbersome step in this se-quence of operations is the solution of the set of algebraic equations. The application of graph theory not only facilitates this solution (of course, only in the linear case), but also provides the possibility of drawing some general conclusions. Let us consider а model catalytic isomerization reaction with the detailed mechanism