AP Chemistryeasymcq1 pt
On a reaction energy profile, what is the arrangement found at the very top of an activation-energy barrier called?
A.The transition state (activated complex)
B.An intermediate
C.A catalyst
D.A stable product
Explanation
Core Concept
The transition state is the highest-energy arrangement along the reaction coordinate, with old bonds partially broken and new bonds partially formed. It sits at the peak of the barrier and survives only about one molecular vibration before relaxing into products or back to reactants. Its energy relative to the reactants defines the activation energy. Unlike an intermediate, it occupies an energy maximum rather than a valley.
Correct Answer
AThe transition state (activated complex)
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