Haloalkanes and Haloarenes - Result Question 39
####39. For the following reactions :
(1) $CH_3 CH_2 CH_2 Br+KOH \to$
[2016] $CH_3 CH=CH_2+KBr+H_2 O$
(2)
(3)
Which of the following statements is correct?
(a) (1) and (2) are elimination reactions and (3) is addition reaction
(b) (1) is elimination, (2) is substitution and (3) is addition reaction
(c) (1) is elimination, (2) and (3) are substitution reactions
(d) (1) is substitution, (2) and (3) are addition reactions
Show Answer
Solution:
(b)
$ \text{ (1) } \begin{aligned} CH_3 CH_2 CH_2-Br+KOH & \text{ m-Bromotoluene } \\ & \to CH_3 CH=CH_2+KBr+H_2 O \end{aligned} $
This is dehydrohalogenation reaction which is an example of elimination reaction.
(2)
Replacement of $Br^{-}$by $OH^{-}$is substitution reaction thus, it is a nucleophilic substitution reaction.
Above reaction involves addition of $Br_2$ across double bond. Thus, it is called addition reaction.
