Nitration of chlorobenzene gives which of the following products?

When chlorobenzene (C₆H₅Cl) undergoes nitration, it reacts with a mixture of concentrated nitric acid (HNO₃) and concentrated sulfuric acid (H₂SO₄), known as the nitrating mixture. This reaction introduces a nitro group (-NO₂) into the benzene ring through an electrophilic substitution mechanism. The major products formed are ortho-chloronitrobenzene and para-chloronitrobenzene.

The chlorine atom already present on the benzene ring has an interesting dual effect. It is electron-withdrawing by induction (-I effect) and electron-donating by resonance (+R effect). Although chlorine slightly deactivates the ring toward electrophilic attack due to its -I effect, it still directs the incoming nitro group to the ortho (2-position) and para (4-position) because of its resonance donation of electron density to the ring. As a result, both ortho- and para-substituted nitro derivatives are obtained, with the para isomer generally being the major product due to less steric hindrance.

The reaction can be represented as:
C₆H₅Cl + HNO₃ → o- and p-ClC₆H₄NO₂ + H₂O (in presence of H₂SO₄)

The ratio of products typically favors p-chloronitrobenzene over the ortho isomer. m-Chloronitrobenzene is not formed because the chlorine substituent is an ortho-para directing group.

This nitration reaction illustrates the combined inductive and resonance effects of halogen substituents on aromatic systems and helps students understand the orientation of substitution in electrophilic aromatic reactions — a fundamental concept in organic chemistry.