Question

Which of the following statements is incorrect about the collision theory of Chemical reaction?
(A) It considers reacting molecules and atoms as hard spheres and ignores their structural features.
(B) Number of effective collisions determines the rate of reaction.
(C) Collisions of atoms or molecules possessing sufficient threshold energy results into the product formation
(D) Molecules should collide with sufficient threshold energy and proper orientation for the collision to be effective.

Answer 1

The reaction in the gas phase is a result of collision of two gas molecules, now not only colliding proceeds the reaction, there are several other functions such as threshold energy, orientation etc. Which leads the reactants to products.

Complete step by step answer
If we want to give the answer to the above asked question, we first need to understand collision theory. The reaction of molecules in gaseous phase happens because of their collision, and therefore, collision theory was introduced to understand its principles.
If a reaction needs to be proceeded in a gaseous phase, the reactants compulsorily have to possess kinetic energy, so it could be used to convert or make bonds.
Now, it is necessary for a molecule to possess minimum activation energy ${E_a}$ to collide and proceed.
Now on increasing the temperature the minimum kinetic energy of the molecule will increase, hence resulting in increasing the rate of reaction.
Now, when bonds are formed and broken we achieve an intermediate term there, which is known as transition State.
Also the orientation of molecules also should be taken into consideration, if their orientation is not accurate they want to be reacting to each other.
Observing the above postulate we can say that option C is incorrect because having a threshold energy is not sufficient we also need proper orientation to proceed a reaction.
Option C is correct.

Note
Collision theory also plays a significant role in ${S_1}$ and ${S_2}$ reactions. The orientation of molecule and atom is also taken into consideration when we study first order substitution reaction and second order substitution reaction.