Subject: Re: CCL:RATE CONSTANT AND BARRIER-QUESTION

From: "J. Sichel" <[email-masked]>
Date: Tue, 29 Dec 1998 15:08:22 -0400 (AST)

On Mon, 28 Dec 1998, E. Lewars wrote:

> True or false:
> 
> Two reactions with exactly the same free energies of activation (delta G
> of activation, not Arrhenius activation energy) _must_ have the same
> rate constants (at the same temperature). 

I can think of two reasons why not.
1. The transition-state-theory expression for k includes a barrier
   transmission coefficent (denoted by kappa) which may vary between
   reactions.
2. Transition-state theory may not be exact for the reactions in question.

     John-M. Sichel
     Dept. de chimie et biochimie
     Universite de Moncton
     Moncton NB, Canada