Haloarenes undergo the usual electrophilic reactions of the benzene ring such as halogenation, nitration, sulphonation and Friedel-Crafts reactions. Halogen atom besides being slightly deactivating is o, p-directing; therefore, further substitution occurs at ortho- and para-positions with respect to the halogen atom. Due to resonance, the electron density increases more at ortho- and para-positions than at meta-positions. Further, the halogen atom because of its –I effect has some tendency to withdraw electrons from the benzene ring. As a result, the ring gets somewhat deactivated as compared to benzene and hence the electrophilic substitution reactions in haloarenes occur slowly and require more drastic conditions as compared to those in benzene.

What is the major product when bromobenzene reacts with nitration mixture? 

1-Bromo-4-nitrobenzene

The correct answer is option 3. 1-Bromo-4-nitrobenzene.

When bromobenzene reacts with a nitration mixture (usually a combination of concentrated nitric acid and concentrated sulfuric acid), the major product is 1-Bromo-4-nitrobenzene.

The bromine atom on the benzene ring is an ortho/para-directing group due to its electron-donating resonance effect, even though it is an overall deactivating group due to its inductive effect. This means that the nitro group will primarily substitute at the ortho and para positions relative to the bromine. Among these, the para position is favored due to less steric hindrance.

So, the correct answer is 1-Bromo-4-nitrobenzene