Organic Compounds Containing Halogens Question 188

Question: Among the following the most reactive towards alcoholic KOH is

[AIIMS 2004]

Options:

A) $ CH_2=CHBr $

B) $ CH_3COCH_2CH_2Br $

C) $ CH_3CH_2Br $

D) $ CH_3CH_2CH_2Br $

Show Answer

Answer:

Correct Answer: D

Solution:

The polarity between C-X bond increase by increasing the +I effect which increase by increasing the alkyl group by which X of C-X easily eliminate.

In $ CH_3CH_2CH_2Br $ the polarity is maximum due to 3 alkyl group while in rest polarity decrease due to the presence of double bond, presence of -CO group (-I) and less no. of alkyl group.

$ CH_3CH_2CH_2Br+KOH\xrightarrow{alc\text{.}} $

$ CH_3CH=CH_2+KBr+H_2O $