Catalysts Reduce Activation Energy

Steps:

• Identify activation energy as the minimum energy required for reactants to form products.
• Recognize that only catalysts directly alter this energy barrier.
• Evaluate each option: catalysts lower Ea, while temperature, concentration, and pressure influence rate or equilibrium differently.
• Confirm A as the sole option that targets Ea.

Why A is correct:

• A catalyst provides an alternative reaction pathway with a lower activation energy, as defined in transition state theory, enabling the reaction to proceed faster without being consumed.

Why the others are wrong:

• B: Decreasing temperature slows the reaction by reducing molecular kinetic energy but does not change the activation energy barrier.
• C: Increasing concentration raises collision frequency, boosting rate but leaving activation energy unchanged.
• D: Increasing pressure shifts equilibrium for gases and may increase rate but does not affect activation energy.

Final answer: A