Question

According to the collision theory, most molecular collisions do not lead to a reaction. Which of the following is(are) necessary for collisions to successfully lead to the reaction?
A. The total kinetic energy of the collision must be greater than some minimum value.
B. A catalyst must be present at the collision.
C. The colliding particles must be properly oriented in space when they collide.
D. None of the above.

Answer 1

Hint: Collision theory is a theory which is used to predict the rates of chemical reactions specifically for gases. The molecules of the reactant species are expected to be of hard spheres and the reactions are assumed to be occurring when the molecules of the species collide with one another. The catalyst is not used in the reaction but it only activates the reaction rate.

Complete step by step answer:
Understanding this question first let us understand the collision theory and its assumptions.
Collision theory is a theory which is used to predict the rates of chemical reactions specifically for gases. This theory is based on some assumptions that if a reaction has to occur it is necessary for the reacting species to collide with one another or come together.
But it is not necessary that if species collide that it will bring about a chemical change. It means that not all collisions can bring chemical change.
The collision can be effective in bringing about a chemical change only if the species which are brought together has some certain minimum value of internal energy. This internal energy should be equal to the activation energy of the reactant. Another condition for the collision to take place and bring about the chemical change is that the colliding species should be oriented in a favourable manner which is necessary for rearrangements of atoms and electrons.
According to the question, the conditions mentioned in option A and option C are necessary for the collision to bring about the chemical change. The option b is not correct because the presence of a catalyst is not essential for collisions. This is due to the fact that reactions can even occur without the presence of a catalyst.

So, the correct answer is Option A,C.

Note: The collision occurs between the species of the reactant but it is not sufficient for the reaction to take place. The collision which occurs should be effective in nature. The effective collisions help us to determine the particles which react with each other so the formation of products occurs.