Question

Match List -I with List II:

Choose the correct answer from the options given below :

• (A) – (IV), (B) – (III), (C) – (I), (D) – (II)
• (A) – (III), (B) – (I), (C) – (II), (D) – (IV)
• (A) – (II), (B) – (IV), (C) – (III), (D) – (I)
• (A) – (I), (B) – (II), (C) – (IV), (D) – (III)

Answer 1

The Correct Option is A

Understand the Effects (Inductive, Resonance, and Electromeric):

E Effect (Electromeric Effect): A temporary effect where a pi bond shifts to one of the atoms in the presence of an attacking reagent.

R Effect (Resonance Effect): The delocalization of electrons in a conjugated system.

+E Effect (Positive Electromeric Effect): Electron pair movement towards the attacking atom.

+R Effect (Positive Resonance Effect): Electron-donating resonance effect, often seen in groups with lone pairs that can donate electron density.

Match Each Mechanism with the Correct Effect:

• (A) Shows a nucleophile attacking and shifting a lone pair, which is a +R effect (IV).
• (B) Shows protonation that increases electron density through resonance, an R effect (II).
• (C) Shows cyanide attaching and shifting electron density, representing +E effect (III).
• (D) Shows electron density shift due to a nitro group, indicating E effect (I).

Conclusion:

The correct matching is:

\[ (A) - (IV), \, (B) - (II), \, (C) - (III), \, (D) - (I) \]

which corresponds to Option (1).

Answer 2

Step 1: Understanding the question.
We are required to match List I (Mechanism steps) with List II (Effect).
The options involve identifying whether each reaction step shows +R effect, −R effect, +E effect, or −E effect based on the movement of electrons and resonance behavior.

Step 2: Analyze each mechanism step.
(A) — The structure shows an −NH₂ group donating electrons to the benzene ring through resonance. This results in electron release by resonance (+R effect) but an electron-withdrawing inductive effect (−E effect). The resonance dominates, so this corresponds to +R effect.
Hence, (A) → (IV).

(B) — Involves the addition of a proton to the benzene ring, leading to the development of a positive charge. This represents an electron-attracting or positive electronic effect (+E effect).
Hence, (B) → (III).

(C) — The structure involves the cyano group (−CN), which strongly withdraws electrons by its −R and −E effects. The electron flow towards the −CN group indicates a −E effect.
Hence, (C) → (I).

(D) — The nitro group (−NO₂) withdraws electrons by both resonance and induction. However, when resonance delocalization of electrons is shown, it indicates a −R effect.
Hence, (D) → (II).

Step 3: Final matching.
\[ \boxed{ (A) – (IV), \, (B) – (III), \, (C) – (I), \, (D) – (II) } \]
Final Answer:
\[ (A) – (IV), \, (B) – (III), \, (C) – (I), \, (D) – (II) \]