Kinetics of the Decomposition of Molecules of Intermediate Complexity

Abstract

IN a large class of gaseous chemical reactions, the mechanism is generally supposed to be the following. Molecules are brought into an activated state by collision. Most of the activated molecules are deactivated again, but during their existence there is a definite probability of their chemical transformation. As is well known, the relation between reaction rate and pressure under these conditions is such that the reciprocal of T, the half life of the reacting substance, gives a curve of type 1 or 2 (see Fig. 1) when plotted against the initial pressure¹. (The precise shape of the curve before it has become horizontal depends upon how the above mentioned probability varies with the total energy of the molecule².)