Question

Aniline reacts with excess Br2/H2O to give the major product

Answer 1

Br2/water is generally used as a test of unsaturation and precipitate formation takes place.

The precipitate is 2,4,6-tribromophenylamine.
see the pic.

Thanks.
Tripathy

Answer 2

Answer : Aniline reacts with excess $Br_2/H_2O$ to give 2,4,6-tribromoaniline as the major product.

Explanation :

The reaction of aniline with excess $Br_2/H_2O$ to give 2,4,6-tribromoaniline as the major product. It is an electrophilic substitution reaction.

As we know that the $-NH_2$ group in aromatic amines behaves as strong ring activators as well as ortho, para directors towards electrophilic substitution reactions.

In the presence of the polar solvents like water, the electrophilicity of the bromine increases. This along with the powerful ring activation by $-NH_2$ group results in the substitution at all the possible ortho and para positions.

The reaction are shown below.