Consider the following reaction that goes from A to B in three steps as shown below: Choose the correct option: | |…
Chemical Kinetics · Class 12 · JEE Main Previous Year Question
Consider the following reaction that goes from A to B in three steps as shown below:
Choose the correct option:
| | Number of Intermediates | Number of Activated Complexes | Rate determining step |
|:---:|:---:|:---:|:---:|
| (1) | 2 | 3 | I |
| (2) | 2 | 3 | III |
| (3) | 2 | 3 | II |
| (4) | 3 | 2 | II |
- a
Option (1)
- b
Option (2)
- c✓
Option (3)
- d
Option (4)
Option (3)
From a 3-step reaction profile:
- Number of intermediates = number of energy minima between reactants and products = 2 (one between steps 1-2 and one between steps 2-3)
- Number of activated complexes (transition states) = number of energy maxima = 3 (one per step)
- Rate determining step = the step with the highest activation energy (highest energy barrier). In the given profile, step III has the highest energy barrier.
Answer: Option (3) — 2 intermediates, 3 activated complexes, RDS = Step III
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