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

• A. It is consumed during the reaction and forms a new product.
• B. It increases the activation energy and decreases the reaction rate.
• C. It changes the equilibrium position of the reaction.
• D. It lowers the activation energy and increases the reaction rate without being consumed.

Answer: (D)

Verified step by step guidance

1. Understand the role of a catalyst in a chemical reaction: a catalyst provides an alternative reaction pathway with a lower activation energy.
2. Recall that activation energy (\[E_a\]) is the minimum energy required for reactants to transform into products, and lowering \[E_a\] increases the reaction rate.
3. Recognize that a catalyst is not consumed in the reaction; it participates temporarily and is regenerated by the end of the process.
4. Know that a catalyst does not change the equilibrium position of the reaction; it only helps the system reach equilibrium faster.
5. Summarize that the correct description is: a catalyst lowers the activation energy and increases the reaction rate without being consumed.