Catalysts lower activation energy without changing molecular energy distribution

Steps:

• Identify peak P as the maximum in the Maxwell-Boltzmann energy distribution curve.
• Note that catalysts do not affect temperature, so the distribution curve remains unchanged.
• Recognize Eₐ as the energy threshold; catalysts reduce it via an alternative pathway.
• Conclude that Eₐ shifts left to a lower energy value on the graph.

Why C is correct:

• By definition, catalysts lower Eₐ (per transition state theory), shifting its position left on the energy axis, while the unchanged distribution keeps peak P at the same height.

Why the others are wrong:

• A: Peak P height unchanged; lowering it implies altered temperature or distribution.
• B: Peak P height unchanged; Eₐ moves right would increase activation energy.
• D: Eₐ moves right incorrectly raises activation energy, opposing catalyst effect.

Final answer: C