How does a catalyst affect the activation energy of a chemical reaction?

• A. It increases the activation energy, slowing down the reaction.
• B. It does not change the activation energy but increases the reactant concentration.
• C. It eliminates the need for activation energy entirely.
• D. It lowers the activation energy, making the reaction proceed faster.

Answer: (D)

Verified step by step guidance

1. Understand that activation energy (E_a) is the minimum energy required for reactants to transform into products during a chemical reaction.
2. Recognize that a catalyst provides an alternative reaction pathway with a lower activation energy compared to the uncatalyzed reaction.
3. Note that by lowering the activation energy, the catalyst increases the number of reactant molecules that have enough energy to overcome this barrier at a given temperature.
4. Understand that this results in an increased reaction rate because more molecules can successfully react per unit time.
5. Remember that a catalyst does not get consumed in the reaction and does not change the reactant concentration or eliminate activation energy entirely; it only lowers the activation energy.