Question

Identify the product formed from chlorobenzene on heating with conc. \(\text{HNO}_3\) in presence of conc. \(\text{H}_2\text{SO}_4\).

• A. Only 1-chloro-4-nitrobenzene
• B. 1-chloro-2-nitrobenzene
• C. Mixture of 1-chloro-4-nitrobenzene and 1-chloro-2-nitrobenzene
• D. 2,4,6-trinitrochlorobenzene

Hint:

Halogens are deactivating but ortho-para directing due to resonance.

Answer 1

The Correct Option is C

Concept:
Nitration of aromatic compounds is an electrophilic substitution reaction. Substituents already present on benzene ring influence the position of incoming group. Step 1: Nature of substituent. Chlorine is:

• Electron withdrawing (\(-I\) effect)
• But ortho-para directing due to resonance

Step 2: Position of substitution. Nitration occurs at: \[ \text{ortho and para positions} \]
Step 3: Products formed.

• 1-chloro-2-nitrobenzene (ortho)
• 1-chloro-4-nitrobenzene (para)

Step 4: Conclusion. A mixture of ortho and para products is formed.