JEE Main Solved Paper 2017 Question 3
Question: The increasing order of the reactivity of the following halides for the $ {S_N}1 $ reaction is $ C{H_3}\underset{Cl}{\mathop{\underset{|}{\mathop{C}},}},HC{H_2}C{H_3} $ $ C{H_3}C{H_2}C{H_2}Cl $ $ p-H _3CO-C _6H _4-CH _2Cl $ [JEE Main Solved Paper-2017]
Options:
A) (III) < (II) < (I)
B) (II) < (I) < (III)
C) < (III) < (II)
D) (II) < (III) < (I)
Show Answer
Answer:
Correct Answer: B
Solution:
For any $ {S_N}1 $ reaction reactivity is decided by ease of dissociation of alkyl halide $ R-X{R^{\oplus }}+{X^{\oplus }} $ Higher the stability of $ {R^{\oplus }} $ (carbocation) higher would be reactivity of $ {S_N}1 $ reaction.
Since stability of cation follows order.
$ CH _3-CH _2-\underset{\oplus }{\overset{\oplus }{\mathop{C}}},H _2 $ $ <CH _3-\overset{\oplus }{\mathop{C}},H-CH _2-CH _3 $ $ <p-H _3CO-C _6H _4-\overset{\oplus }{\mathop{C}},H _2 $
