Which of the following best describes how a catalyst benefits a chemical reaction?

• A. It provides additional reactants to speed up the reaction.
• B. It increases the equilibrium constant, making the reaction more favorable.
• C. It changes the products formed by the reaction.
• D. It lowers the activation energy, increasing the reaction rate without being consumed.

Answer: (D)

Verified step by step guidance

1. Understand that a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process.
2. Recall that the catalyst works by providing an alternative reaction pathway with a lower activation energy, which is the minimum energy required for reactants to transform into products.
3. Recognize that lowering the activation energy increases the number of effective collisions per unit time, thus speeding up the reaction.
4. Note that a catalyst does not change the equilibrium constant or the position of equilibrium; it only helps the system reach equilibrium faster.
5. Also, understand that a catalyst does not provide additional reactants nor does it change the products formed by the reaction.