Alkyl Halides - Result Question 5
####5. Which of the following potential energy (PE) diagrams represents the $S _N 1$ reaction?
(2019 Main, 9 April II)
(a)
(b)
(c)
(d)
Show Answer
Answer:
Correct Answer: 5. (b)
Solution:
- The potential energy (PE) diagram for $S _N 1$ reaction is
$S _N 1$ reaction has two steps. In the first step, the carbon halogen bond breaks heterolytically, with the halogen retaining the previously shared pair of electron. In the second step, the nucleophile reacts rapidly with the carbocation formed in the first step.
In the above graph, the alkyl halide is the only species that participates in the rate limiting step. Here, the rate of reaction depends on the concentration of the alkyl halide and does not depend on the concentration of nucleophile.
