The function of a catalyst in a chemical reaction is to:

The correct answer is Option (3) → Accelerate the rate of reaction

• A catalyst is a substance that increases the rate of a reaction without itself undergoing any permanent chemical change. It provides a different path with a lower activation energy, so the reaction goes faster.

• It speeds up the forward and backward reactions to the same extent, so equilibrium is reached sooner but its position does not change.

Why the other options are incorrect

Option (1) Increase the product — Incorrect. A catalyst does not change the equilibrium constant, so the amount of product at equilibrium stays the same; it is only reached faster.

Option (2) Decrease the product — Incorrect. For the same reason, a catalyst does not lower the amount of product either. A substance that slows a reaction is called an inhibitor, not a catalyst.

Option (4) Increase the reactants — Incorrect. A catalyst adds no reactant and is not used up; the amounts of reactants are set by what is taken and by the equilibrium.

NCERT (2026-27 edition):
3.4.1 Effect of Catalyst – “A catalyst is a substance which increases the rate of a reaction without itself undergoing any permanent chemical change.”