Excerpt from Quantum Theory of Chemical Reaction Rates
We shall discuss the rate constant for a simple bimolecular reaction -
(1) AB + C -> A + BC
where A, B and C are atoms or molecules. The rate constant for this reaction will in general be given by an expression of the form-E kT
(2) kfo(T)=pfoze^-Eact/kT,
where Z is the number of collisions of AB and C per second(~ 10^9-13 , or less depending on density); it is defined in terms of an effective molecular radius and thus is clearly not a very precise concept. Eact (~ 5-50 Kcal/mole, i.e., 0.2-2 ev) is the "activation energy," and Pfo(~ 10^-3 -l)a "steric factor". Both Pfo and Z will be mildly temperature dependent, but the principal - and very striking - temperature variation of the rate constant arises from the activation energy. The problem is thus to explain the character of the expression (2) for the rate constant.
The standard interpretation of(2) is that there must exist an "activated state" (ABC), whose energy is Eact above that of AB + C at infinite separation. We say that this state must be formed if there is to be a reaction (l). Once the state has been formed it will have some definite (statistical) life time, after which it can presumably break up into AB + C or into A + BC, both of which will in general be energetically accessible from (ABC).
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works. Это и многое другое вы найдете в книге Quantum Theory of Chemical Reaction Rates (Classic Reprint) (Ernest Bauer)