MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Dehydrohalogenation for Alkenes

Which of the ...

Question

Which of the following compound(s) will not undergo $β$ - Elimination reaction on reacting with alcoholic KOH?

A

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

B

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct options are
A
D
When an alkyl halide is treated with alcoholic KOH ( KOH dissolved in alcohol) it undergoes dehydrohalogenation to give alkene as product.
Removal of the halogen atom together with a hydrogen atom from a carbon adjacent to the one bearing the halogen. Since hydrogen is eliminated from the $β$ carbon atom, the dehydrohalogenation of alkyl halide is also known as β-Elimination reaction.
So for this particular reaction to proceed there should be a $β$ -hydrogen in the molecule.
In compound (a) and (d), there is no $β$ -hydrogen so they don't undergo elimination reaction in presence of alcoholic KOH.
Compound (b) has 2 $β$ -Hydrogen and compound (c) has 1 $β$ -Hydrogen so they undergo $β$ Elimination.

Suggest Corrections

thumbs-up

0

Similar questions

Q. Arrange the following alkyl halides in increasing order of the rate of

β

-elimination reaction with alcoholic

K O H

Q. The correct decreasing order of stability of alkene formed from the following alkyl halides according to the

β -

elimination reaction with alcoholic KOH will be:
(i)

C H_{3} - C H_{2} - B r

C H_{3} - C H_{2} - C H_{2} - B r

Q. Which of the following compounds undergoes dehydrochlorination most easily when treated with alcoholic

K O H

Q. The correct decreasing order of following alkyl halides according to the rate of

β

- elimination reaction with alcoholic KOH will be:
(i)

{C H}_{3} - H | C | {C H}_{3} - {C H}_{2} B r

C H_{3} - C H_{2} - B r

C H_{3} - C H_{2} - C H_{2} - B r

Q. Arrange the following alkyl halides in decreasing order of the rate of

β

-elimination reaction with alcoholic KOH.

{C H}_{3} {C H}_{2} {C H}_{2} B r (i)

{C H}_{3} - C H {- C H}_{2} B r | {C H}_{3} (i i)

{C H}_{3} - {C H}_{2} - C H - {C H}_{3} | B r (i i i)

View More

Join BYJU'S Learning Program

explore_more_icon

Explore more

Dehydrohalogenation for Alkenes

Standard XII Chemistry

Join BYJU'S Learning Program

CrossIcon