Which of the following best describes the effect of a catalyst on a chemical reaction?

• A. It lowers the activation energy, increasing the reaction rate without being consumed.
• B. It increases the activation energy, slowing down the reaction.
• C. It is consumed during the reaction and becomes part of the products.
• D. It changes the equilibrium position of the reaction.

Answer: (A)

Verified step by step guidance

1. Understand that a catalyst is a substance that affects the rate of a chemical reaction without being consumed in the process.
2. Recall that the activation energy is the minimum energy required for reactants to transform into products during a reaction.
3. Recognize that a catalyst works by providing an alternative reaction pathway with a lower activation energy, which increases the reaction rate.
4. Note that although a catalyst speeds up the reaction, it does not change the overall equilibrium position or the thermodynamics of the reaction.
5. Conclude that the best description of a catalyst's effect is that it lowers the activation energy, increasing the reaction rate without being consumed.