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AP® Chemistry

Free Version
Moderate

APCHEM-BMQYSU

Consider the three statements about reaction energy diagrams and the relative magnitudes of the activation energy, ${E}_{a}$, and the enthalpy of reaction, $\Delta{H}$.

Statement
I For an endothermic reaction, the magnitude of ${E}_{a}$ is always greater than $\Delta{H}$.
II For an exothermic reaction, the magnitude of ${E}_{a}$ is always greater than $\Delta{H}$.
III For an exothermic reaction, adding a catalyst will decrease the magnitude of $\Delta{H}$.

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Which of the following statements IS CORRECT?

A

Statement I only is true.

B

Statement II only is true.

C

Both Statements I and II are true.

D

Both Statements I and III are true.