Question

Collision theory vs transition state theory equations

Answer 1

Answer:

Transition-State Theory. Transition state theory (TST) provides a more accurate alternative to the previously used Arrhenius equation and the collision theory. ... According to TST, between the state where molecules are reactants and the state where molecules are products, there is a state known as the transition state.

Explanation:

the authors mentioned that collision theory applies only to gas phase reactions while transition state theory is a generalization to reactions in solution. For the gas phase reactions, it was derived that where P = steric factor, = cross sectional area, NA = Avogadro's #.

I don't really understand why we can't generalize this to reactions in solution. Is this because the mean free path of a reactant in solution is much smaller than in gaseous phases, and that the solvent molecules will interfere with the mean relative speed of the reactants? In this case, will the Boltzmann distribution change for the energy, since the reactants are getting energy from external sources (i.e. the solvent molecules that they bump into) instead of relying purely on their own kinetic energy? Would the solvent molecules (and reactant-solvent collisions) make it easier or harder for reactants to overcome the activation energy barrier and reach the activated complex?