Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Haloalkanes and Haloarenes

Question:

Case: Read the passage and answer the questions

There are several methods to prepare halo alkanes and haloarenes. One of the methods is to prepare from alcohol. The hydroxyl group of an alcohol is replaced by halogen on reaction with concentrated halogen acids, phosphorus halides or thionyl chloride. The halo alkanes are prepared by treating alkane with a limited amount of halogen in presence of halogen carrier and sunlight or heat. Adding hydrogen halide to alkene also results in the formation of halo alkanes. Haloarenes are prepared from hydrocarbons by electrophilic substitution and amines by Sandmeyer’s reaction.

What type of reaction is bromination of methane in presence of sunlight?
Options:
Free radical substitution
Nucleophilic substitution
Electrophilic substitution
None of the above
Correct Answer:
Free radical substitution
Explanation:
This reaction between methane and bromine happens in the presence of ultraviolet light - typically sunlight. This is a good example of a photochemical reaction - a reaction brought about by light.