Question

Which of the following alkane(s) on halogenation gives only only one monohalogenated product?

• A. n-butane
• B. 2-methylbutane
• C. 2,2-dimethylpropane
• D. Cyclopentane

Answer 1

Answer: (C), (D)

The correct options are
C 2,2-dimethylpropane
D Cyclopentane

Halogenation :
When one or more H atoms of an alkane are replaced by halogens, the reaction is called as a halogenation reaction.
It takes place at high temperature (573 to 773K) and in presence of diffused or ultraviolet (UV) light.

For (a) : Two mono halogenated products are possible as shown :


Halogenation at carbon 3 and carbon 4 will yield similar products as (b) and (a) respectively.
For 2-methylbutane,4 mono halogenated products are possible as shown :

For (c) and (d) : All the carbon atoms are similar and mono halogenation at any carbon atom gives a single product.