- #1
loom91
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Hi,
In all derivations of the Eyring equation I've seen, all the steps are carried out in detail until the end, when suddenly the rate of the uni-molecular reaction (transition state -> products) is set to kT/h without justification. Why can all transition states be assumed to react at this rate?
This seems particularly strange since from the viewpoint of a transition state there is no difference between 'reactant' and 'product', but the rate of the reaction (TS -> reactants) is not set equal to this value! What is happening here? What is the justification behind assuming equilibrium (reversibility) between reactants and TS but not TS and products?
Also, do all reactions with a given reactant and product pass through the same transition state? TS is the saddle point of potential energy and thus the easiest path to take, but should not the actual reaction proceed through a statistical distribution of paths clustered around the one passing through the TS?
This is actually a question of physical chemistry, but to me it seems to have to do more with quantum physics than chemistry, that's why I'm posting it here. Thanks for the help.
Molu
In all derivations of the Eyring equation I've seen, all the steps are carried out in detail until the end, when suddenly the rate of the uni-molecular reaction (transition state -> products) is set to kT/h without justification. Why can all transition states be assumed to react at this rate?
This seems particularly strange since from the viewpoint of a transition state there is no difference between 'reactant' and 'product', but the rate of the reaction (TS -> reactants) is not set equal to this value! What is happening here? What is the justification behind assuming equilibrium (reversibility) between reactants and TS but not TS and products?
Also, do all reactions with a given reactant and product pass through the same transition state? TS is the saddle point of potential energy and thus the easiest path to take, but should not the actual reaction proceed through a statistical distribution of paths clustered around the one passing through the TS?
This is actually a question of physical chemistry, but to me it seems to have to do more with quantum physics than chemistry, that's why I'm posting it here. Thanks for the help.
Molu