Answer: Option (d) is the correct answer.
Explanation:
A catalyst is defined as the substance that helps in increasing the rate of a chemical reaction by lowering the activation energy. A catalyst never gets consumed in a chemical reaction.
When a catalyst lowers the activation energy then molecules with much less energy are also able to participate in the chemical reaction. Hence, formation of products occur rapidly and thus rate of reaction increases.
Therefore, we can conclude that the catalyst is unchanged and is separate from the products after a chemical reaction has occurred.
