Which of the following best explains how catalysts increase the rate of a chemical reaction?

• A. They increase the concentration of the products.
• B. They increase the temperature of the reactants.
• C. They change the equilibrium position of the reaction.
• D. They lower the activation energy required for the reaction to occur.

Answer: (D)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on the activation energy, which is the minimum energy required for reactants to transform into products.
2. Recognize that catalysts work by providing an alternative reaction pathway with a lower activation energy, making it easier for reactants to convert into products.
3. Note that catalysts do not change the concentration of products or reactants directly, nor do they alter the temperature of the system.
4. Understand that catalysts do not shift the equilibrium position; instead, they help the system reach equilibrium faster by speeding up both the forward and reverse reactions equally.
5. Therefore, the best explanation for how catalysts increase reaction rates is that they lower the activation energy required for the reaction to occur.