How does a catalyst speed up a chemical reaction?

• A. It provides additional reactants to the reaction mixture.
• B. It raises the temperature of the reaction mixture.
• C. It increases the equilibrium constant of the reaction.
• D. It lowers the activation energy required for the reaction to occur.

Answer: (D)

Verified step by step guidance

1. Understand that a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process.
2. Recall that the speed of a reaction depends on the activation energy, which is the minimum energy required for reactants to transform into products.
3. Recognize that a catalyst works by providing an alternative reaction pathway with a lower activation energy, making it easier for reactants to convert into products.
4. Note that a catalyst does not change the temperature of the reaction mixture or add more reactants; it only affects the energy barrier.
5. Also understand that a catalyst does not change the equilibrium constant, which depends only on the thermodynamics of the reaction, not on the reaction pathway.