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NEET CHEMISTRYHaloalkanes and HaloarenesMedium

Question

Identify the statement that is incorrect regarding chirality:

A

A racemic mixture shows zero optical rotation

B

SN1\text{S}_\text{N}1 reaction yields a 1:1 mixture of both enantiomers

C

The product obtained by SN2\text{S}_\text{N}2 reaction of haloalkane having chirality at the reactive site shows the inversion of configuration

D

Enantiomers are superimposable mirror images on each other

Step-by-Step Solution

The incorrect statement is that enantiomers are superimposable mirror images. By definition, the stereoisomers related to each other as non-superimposable mirror images are called enantiomers . The other statements are correct:

  1. A racemic mixture contains equal proportions of two enantiomers, so the optical rotation of one isomer is cancelled by the other, resulting in zero optical rotation .
  2. In an SN1\text{S}_\text{N}1 reaction, the intermediate carbocation is planar, allowing nucleophilic attack from either face, which results in racemisation (a 1:1 mixture of enantiomers) .
  3. An SN2\text{S}_\text{N}2 reaction proceeds with the nucleophile attacking from the side opposite to the leaving group, resulting in an inversion of configuration .

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Haloalkanes and Haloarenes. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYHaloalkanes and Haloarenesidentifystatementincorrectregardingchirality

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