JEE Chemistry 2026 Question with Solution

Given: Four aryl diazonium salts A, B, C, D are shown.

Find: The correct stability order.

Step 1: Basic stability rule for diazonium salts. Aryl diazonium salts are stabilized by electron donating groups on the benzene ring and destabilized by strong electron withdrawing groups.

Step 2: Effect of substituents.

• (A) $-OCH_3$: Strong $+M$ electron donating effect, stabilizes the diazonium ion greatly.
• (C) $H$: No substituent effect, moderate stability.
• (D) $-CN$: Strong $-M$ effect, reduces stability.
• (B) $-NO_2$: Very strong $-M$ and $-I$ effects, maximum destabilization.

Step 3: Ordering stability.

$$\text{A (most stable)} > \text{C} > \text{D} > \text{B (least stable)}$$

Step 4: Final conclusion. Therefore, the correct stability order is A $>$ C $>$ D $>$ B. The correct option is A.

Given: Stability depends on how the substituent affects the aryl diazonium ion.

Find: Which sequence matches the relative stabilizing and destabilizing effects.

Electron donation by resonance increases stability, while electron withdrawal by resonance and induction decreases it. Therefore:

• $-OCH_3$ donates by resonance strongly, so A is most stable.
• Unsubstituted benzene diazonium salt C has no special stabilization or destabilization.
• $-CN$ withdraws electrons, so D is less stable than C.
• $-NO_2$ is the strongest withdrawing group here, so B is least stable.

Thus the order is:

$$\text{A} > \text{C} > \text{D} > \text{B}$$

So the correct option is A.