A catalyst provides an alternative reaction pathway with what effect on activation energy?

• A. Higher activation energy
• B. The same activation energy
• C. A completely different reaction
• D. Lower activation energy

Answer: (D)

A catalyst works by providing an alternative reaction pathway that has a lower energy barrier. Activation energy is the minimum energy needed for reactants to transform into products. By offering a route that requires less energy, more reacting particles have enough energy at a given temperature to react, so the rate of the reaction increases. Catalysts don’t change the overall energy change or end products; they only speed things up by lowering the barrier. They don’t make the reaction energetically harder, keep the barrier unchanged, or create an entirely different reaction.