What is the effect of a catalyst on a reaction? It increases the entropy. It decreases the entropy. It changes the equilibrium. It makes the products more stable.

It increases the entropy

Explanation:

Entropy is the measure of degree of randomness or disorder.

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products. Thus leading to more randomness and more entropy.