Question

What is the role of a catalyst in a chemical reaction?

Answer 1

Catalysts are the chemical substances which increase the rate of a chemical reaction. It does not get consumed itself in any chemical reaction but modifies the way or direction in which the chemical reaction is taking place so that the activation energy needed for the chemical reaction gets lower and can be reached easily.

Complete answer:
Now, we know that catalysts are the chemical substances which help to increase the rate of the reaction by taking such a pathway so that the activation energy of the reaction decreases.
For example:
If we take the example of decomposition of potassium chlorate to give potassium chloride and oxygen and the reaction is as follows:
$2KCl{O_3} \to 2KCl + 3{O_2}$
Therefore, in the above reaction, Manganese dioxide is used as a catalyst which increases the rate of the reaction. It does not get consumed in the chemical reaction.
Role of a catalyst in a chemical reaction:
- A catalyst is a chemical substance which helps to increase the rate of the reaction.
- It makes the reaction proceed faster by adjusting the activation energy of that reaction or by changing the mechanism of the reaction.
- It does not get consumed by itself in the reaction.

Note :
Activation energy is the minimum amount of energy required for a reaction to start. Catalyst does not change the equilibrium constant of the reaction but accelerates the backward or forward reactions to reach the equilibrium rapidly. A catalyst can only catalyse a spontaneous reaction (a reaction which occurs by itself).