Question

Define a bimolecular reaction. Explain the conditions of effective collisions of bimolecular reactions.

Answer 1

Hint: Max Trautz and William lewis gave collision theory in 1916-1918. The collision theory is given in relation with the kinetic theory of gases. The theory explains the behavior of gases as they move in a random direction and collide with each other.

Complete step by step answer:
Collision theory: According to collision theory, the molecules are supposed to be a hard sphere and the reaction only takes place when the two spheres or the molecules collide with one another.

Bimolecular reaction: The bimolecular reaction is defined as the reaction where two reactant molecules collide with each other to form the product.
The general bimolecular reaction is given as shown below.
$P + Q \to Product$
The example of bimolecular reaction is shown below.
$2NOCl \to 2NO(g) + C{O_2}(g)$
In this reaction, two mole of nitrosyl chloride react to give two mole of nitric oxide and one mole of carbon dioxide.

There are mainly two conditions for causing an effective collision between the reactant molecules in a bimolecular reaction.
(1) The two molecules should collide with sufficient amounts of kinetic energy. This energy is also known as threshold frequency or activation energy.
The activation energy is defined as the minimum energy required for the two reactant species to carry out the reaction to form the resulting product.
(2) The molecules should possess proper orientation.
Thus, the rate of reaction is given by
\[Rate = P{Z_{PQ}}{e^{\dfrac{{ - Ea}}{{RT}}}}\]
Where
P is the probability factor
${Z_{PQ}}$ is the collision frequency of both the reactant
${E_a}$ is the activation energy
R is the universal gas constant
T is the temperature

Note: To initiate the reaction firstly the bonds between the atoms in the reactant molecule should be broken. So, activation energy is given before the reaction takes place.