Collision Theory

Collision Theory
For a reaction to take place,certain conditions must be fulfilled.Like we all know, reactions are made up of both reactants and products and for a given reaction to occur without obstacles, the minimum amount of energy required for such reaction to take place must be overcome.Certain factors are necessary for a faster reaction rate in terms of reaction kinetics.  However, when molecules/atoms collide with each other, collision is bound to occur.Having a clear knowledge that the rate constant depends on temperature and can be explained by collision theory.

Collision theory of reaction rates is a theory that assumes that, for reaction to occur, reactant molecules must collide with an energy greater than some minimum value and with the proper orientation. The minimum energy of collision required for two molecules to react is called the activation energy, Ea. The value of Ea depends on the particular reaction.

In collision theory, the rate constant for a reaction is given as a product of three factors:
(1) Z, the collision frequency

(2) f, the fraction of collisions having energy greater than the activation energy,and

(3) p, the fraction of collisions that occur with the reactant molecules properly oriented.
Thus, k ==>Zfp