Which statement best describes the role of a catalyst in a chemical reaction?

• A. A catalyst is permanently altered and consumed during the reaction.
• B. A catalyst increases the rate of a reaction without being consumed in the process.
• C. A catalyst decreases the activation energy and is converted into a product.
• D. A catalyst slows down the reaction by increasing the activation energy.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand what a catalyst is in the context of chemical reactions. A catalyst is a substance that affects the rate of a reaction without undergoing permanent chemical change itself.
2. Step 2: Recall that catalysts work by providing an alternative reaction pathway with a lower activation energy, which increases the reaction rate.
3. Step 3: Recognize that because catalysts are not consumed or permanently altered, they can participate in multiple reaction cycles.
4. Step 4: Eliminate incorrect statements: a catalyst is not consumed or converted into a product, and it does not slow down the reaction or increase activation energy.
5. Step 5: Conclude that the best description is that a catalyst increases the rate of a reaction without being consumed in the process.