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

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

Answer: (B)

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 while a catalyst speeds up both the forward and reverse reactions equally, it does not change the equilibrium position or the overall thermodynamics of the reaction.
5. Conclude that the correct description of a catalyst's effect is that it lowers the activation energy, increasing the reaction rate without being consumed.