What is the statistical or probability theory of chemical kinetics?

Question

Details regarding probability concpt in reaction kinetics.

Answer 1

A full answer would take pages.  But here is the basic idea:

For a chemical reaction to take place, the reactants have to meet with sufficient energy to overcome the activation energy barrier (there is a certain probability of this, increasing with temperature according to the Arrhenius equation).  In addition, they have to hit each other at the correct angle, and even if they do it is not certain, according to quantum mechanics, that they will actually react, so this gives you a temperature-independent term in the rate.

Or, if it is a unimolecular reaction step, there is a certain probability that the energy will find itself in the right place in the molecule.