Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A): undergoes S N 2 reaction faster than Reason (R): Iodine is a better leaving group because of its large size. In light of the above statements, choose the most appropriate answer from the options given below.

Both A and R are true and R is the correct explanation of A .

Both A and R are true but R is not the correct explanation of A .

Chemistry · Alkyl and Aryl Halides

NEET (UG) 2025 — Question 77

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A):

structure

undergoes S $_\mathrm{N}$ 2 reaction faster than

structure

Reason (R): Iodine is a better leaving group because of its large size.

In light of the above statements, choose the most appropriate answer from the options given below.

Option A:
Both $\mathbf{A}$ and $\mathbf{R}$ are true and $\mathbf{R}$ is the correct explanation of $\mathbf{A}$ .
Correct
Option B:
Both $\mathbf{A}$ and $\mathbf{R}$ are true but $\mathbf{R}$ is not the correct explanation of $\mathbf{A}$ .
Option C:
$\mathbf{A}$ is true but $\mathbf{R}$ is false
Option D:
$\mathbf{A}$ is false but $\mathbf{R}$ is true

Answer: A

Step-by-step solution

Glucose contains an aldehyde group. It reduces Tollen's reagent ( $\ce{Ag(NH3)2+}$ ) to give a silver mirror. It adds HCN to form a cyanohydrin. It reacts with $\ce{NH2OH}$ (hydroxylamine) to form an oxime. Glucose does not give Schiff's test because the aldehyde is involved in cyclic hemiacetal formation. It does not form a bisulfite addition product with $\ce{NaHSO3}$ for the same reason. Thus, the reagents with which glucose does NOT react are B (Schiff's reagent) and E ( $\ce{NaHSO3}$ ). Hence, the correct option is C (B and E).

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Exam: NEET (UG) 2025
Paper: 2025 paper
Subject: Chemistry
Chapter: Alkyl and Aryl Halides
Topic: Mechanism of Substitution reactions

How many products (including stereoisomers) are expected from monochlorination of the following compound? ceCH3-CH(CH3)-CH2-CH3

Answer: A

Step-by-step solution

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