Question

In terms of the ‘Collision Theory of Chemical Kinetics’, the rate of a chemical reaction is proportional to:
A. The change in free energy per second
B. The change in temperature per second
C. The number of collisions per second
D. The number of product molecules

Answer 1

Hint: We must know that the rate of a chemical reaction is proportional to the number of collisions per second as proper collision leads to a chemical reaction. Therefore, more reactant molecules collide with one another which increase the reaction rate.

Complete step by step answer:
In order for a chemical reaction to occur between reactants it requires the collisions between reactant molecules. Also the reactant collisions must be of proper orientation and sufficient energy in order to result in product formation. We can get a simple but effective explanation for the effect of many experimental parameters on reaction rates from Collision theory.
Firstly we must understand the concept of collision theory:
According to the collision theory,
(1) The reactants must collide with sufficient energy, known as the activation energy, so that chemical bonds between the atoms can break.
(2) The molecules must collide with a proper orientation.
(3) As the temperature rises, molecules move faster and collide more vigorously, increasing the chance of bond breakage upon collision.
Now it is observed that the rate of a chemical reaction is directly proportional to the number of collisions per second as proper collision leads to a chemical reaction.
Hence, the correct option among the following is C.
Note:
We must know that the rate of a chemical reaction is the measure of the change in concentration of a reactant or product per unit time. We can express in terms of the rate of decrease in the concentration of any of the reactants or the rate of increase in the concentration of any of the products.