Select the correct answer. Which statement is true about a catalyst? A. A catalyst decreases the rate of the reaction. B. A catalyst is consumed during a chemical reaction. C. A catalyst lowers the activation energy of a reaction. D. A catalyst increases the reactant concentration during a reaction.

Answer: C. A catalyst lowers the activation energy of a reaction.

Explanation:

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 convert to products.

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

The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.

Your most probable answer is D.