[Johnny010]

Hey there. A problem:

Explain why TST generally predicts an 'A factor' of less than K_bT/h ?

So far I have gotten this from TST:

A quasi-eqm assumption;

A+B [AB]^‡ :rarrow:P

K^‡=[AB]^‡/[A]

[AB]^‡=K^‡[A]

Rate equation for P;

d[P]/dt = k^‡[AB]^‡
d[P]/dt = k^‡K^‡[A]
d[P]/dt = k[A]   where k^‡K^‡=k

k^‡ is proportional to the vibration mode responsible for the conversion of the [AB]^‡ into P.
k^‡=_kν         Where ν is the frequency of the vib. mode and _k is the constant for the proportionality.

K^‡=K_bT/hν * K^‡'
Where K^‡' = e^-:delta:G/RT

k=k^‡K^‡ = _kK_bT/h * e^-:delta:G/RT

As  :delta:G =  :delta:H - T :delta:S

k=_kK_bT/h * e ^{:delta:S‡/R} * e^-:delta:G/RT