Match List-I with List-II
|
List-I |
List-II |
|
(A) \( {S_N}^2 \) |
(I) Racemization |
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(B) Iodoform |
(II) Ozone depletion |
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(C) \( {S_N}^1 \) |
(III) Antiseptic |
|
(D) Carbon tetrachloride |
(IV) Inversion |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
The list mixes the stereochemistry of the two nucleophilic substitution mechanisms with uses and effects of two polyhalogen compounds.
(A) \(S_N2\) — This matches (IV) Inversion. The nucleophile attacks the carbon from the side opposite to the leaving halogen in a single step, so the configuration is inverted, like an umbrella turned inside out:
\( \displaystyle (-)\text{-}\ce{CH3(CH2)5CHBrCH3} + \ce{OH-} \xrightarrow{S_N2} (+)\text{-}\ce{CH3(CH2)5CH(OH)CH3} + \ce{Br-} \)
(B) Iodoform — This matches (III) Antiseptic. Iodoform, \( \ce{CHI3} \), was used as an antiseptic; its action comes from the free iodine it releases, not from iodoform itself.
(C) \(S_N1\) — This matches (I) Racemization. The halide first leaves to give a planar carbocation, which the nucleophile can attack from either face; an optically active halide then gives a racemic mixture:
\( \displaystyle \ce{R3C-Br -> R3C^+ + Br^-}\quad\text{(slow)};\qquad \ce{R3C^+ + OH^- -> R3C-OH}\quad\text{(fast)} \)
(D) Carbon tetrachloride — This matches (II) Ozone depletion. \( \ce{CCl4} \) released into the air rises to the upper atmosphere, where its chlorine atoms break down the ozone layer.
Shortcut: (A)-(IV) appears only in Option (3).