Match List I with List II :
Choose the correct answer from the options given below :

Solution

Chemistry ma’am · 3 steps

First ask if a reagent is present: that makes it E, not R. Then ask which way the electrons move.

1. R or E. The resonance (R) effect is permanent: electrons are delocalised in the molecule even with no reagent nearby. The electromeric (E) effect is temporary: a multiple bond shifts its π electrons only when a reagent attacks. A and D are resonance structures of one molecule. B and C each show a reagent attacking C=C.
2. Sign of each effect. +R: the group pushes electrons into the ring. −R: the group pulls electrons out of the ring. +E: the π electrons move to the carbon where the reagent bonds, which happens with an electrophile such as H⁺. −E: the π electrons move to the other carbon, away from the reagent, which happens with a nucleophile such as CN⁻.

   Step	What the arrows show	Effect
   A	Lone pair on NH₂ pushed into the ring, giving =NH₂⁺ and a ring carbanion	+R (IV)
   B	π electrons go to the carbon that takes H⁺, and the other carbon becomes C⁺	+E (III)
   C	CN⁻ bonds to one carbon, and the π electrons move to the other carbon as C⁻	−E (I)
   D	Ring π electrons pulled onto NO₂, giving O⁻ and a ring carbocation	−R (II)

3. So. A–IV, B–III, C–I, D–II, which is option (d).

The idea to keep. No reagent means R; a reagent attacking a multiple bond means E. For E, electrons moving toward the attacker means +E (electrophile), and moving away means −E (nucleophile).

Answer from the NTA final answer key. Solution by PrepWiser.