Question

According to collision theory:
A.all collisions are sufficiently violent
B.all collisions are responsible for product formation
C.all collisions are effective
D.only a fraction of collisions are effective which have enough energy to form products

Answer 1

Collision theory is used to predict the rate of chemical reactions, particularly for gases. The theory is based on the assumption that for a reaction to occur it is necessary for the reacting species to come together or collide with one another.

Complete step by step answer:
The collision theory is used to predict the rate of chemical reactions. The theory states that, in order for a chemical reaction to occur the molecules of the reacting species must collide with each other and form products. It also states that not all collisions bring about chemical change. A collision will be effective only if the species brought together possess a minimum value of internal energy, equal to the activation energy of the reaction. It also states that the colliding species must be oriented in a manner favourable to the necessary rearrangement of atoms and electrons. Thus, depending upon these two factors, the rate of chemical reaction is equal to the frequency of effective collisions. So, we can say that only a fraction of collisions are effective which have enough energy to form products.

$\therefore$ The correct option is option D, i.e. only a fraction of collisions are effective which have enough energy to form products.

Note:
Based on the collision theory and temperature dependence of the reaction rates, an equation is formulated known as the Arrhenius equation. The formula is:
${\text{k = A}}{{\text{e}}^{\dfrac{{ - {\text{Ea}}}}{{{\text{RT}}}}}}$ where k is the rate constant of a reaction, A is the collision factor, ${{\text{E}}_{\text{a}}}$ is the activation energy of the reaction, R is a constant and T is the temperature.