Question

The product formed when benzene is nitrated by fuming nitric acid is
A. m-dinitrobenzene
B. Nitrobenzene
C. sym-trinitrobenzene
D. None of these

Answer 1

Hint: Benzene is an electron dense species due to presence of pi electrons. It can donate its electron pair. On reaction with nitric acid it undergoes nitration reaction and forms nitrobenzene as a product.

Complete Step by Step Answer:
Benzene is a nucleophile due to the presence of high electron density. On nitration the electrophile nitro group can easily attack any position of benzene and form a product. Benzene on fuming with nitric acid means the reaction takes place in presence of water.

Water is a polar solvent which activates the benzene ring so much that on treatment with nitric acid in water the electrophile or the nitro group attacks the ortho, meta and one para positions at a time and gives sym-trinitrobenzene as a major product along with three moles of water.

The nitration reaction of benzene is as follows:

Thus the correct option is C.

Note: Nitration reaction is an aromatic electrophilic substitution reaction where an electrophile attacks a benzene ring. In the nitration of the benzene ring the nitro group acts as an electrophile due to low electron density and it easily attacks the more electron dense system that is the benzene ring to give product.