Question

Chlorobenzene on heating with concentrated $\text{HNO}_3$ in presence of concentrated $\text{H}_2\text{SO}_4$ gives

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

Halogens attached to a benzene ring are unique: they are deactivating due to their strong inductive effect, but they are always ortho/para-directing due to resonance.
The para-product is almost always the major product because it minimizes steric clash between adjacent functional groups.

Answer 1

The Correct Option is A

Step 1: Understand the question.
Chlorobenzene is heated with concentrated $HNO_3$ and concentrated $H_2SO_4$. We must find the product shown in the options.
Step 2: Spot the reaction type.
This acid mixture makes the nitronium ion ($NO_2^+$), which adds a nitro group to the ring. This is nitration.
Step 3: Find where chlorine sends the group.
Chlorine has lone pairs that feed the ring at the ortho and para positions, so the nitro group goes there even though chlorine is weakly deactivating.
Step 4: Compare ortho and para.
The ortho position is next to the bulky chlorine, so crowding makes it the minor product. The para position is open, so it is favoured.
Step 5: Name the major product.
The main product is 1-chloro-4-nitrobenzene, the para isomer, along with a smaller amount of the ortho isomer. This combination is shown in option 1.
Step 6: Choose the answer.
The correct product set is option 1. \[ \boxed{\text{para (major) + ortho (minor)}} \]