Question

The incorrect statement regarding chirality is:

• A. SN₁ reaction yields 1:1 mixture of both enantiomers.
• B. The product obtained by SN₂ reaction of haloalkane having chirality at the reactive site shows inversion of configuration.
• C. Enantiomers are superimposable mirror images on each other.
• D. A racemic mixture shows zero optical rotation.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Chirality is the property of non-superimposability of an object on its mirror image.
Chiral molecules lack a plane or center of symmetry.
Detailed Explanation:
Evaluating the options:
(1) Correct Statement: In $S_{N}1$ reactions, a planar carbocation intermediate is formed.
The nucleophile can attack from either face, leading to racemization (1:1 mixture of enantiomers).
(2) Correct Statement: In $S_{N}2$ reactions, the nucleophile attacks from the side opposite the leaving group.
This leads to a complete inversion of configuration (Walden inversion).
(3) Incorrect Statement: By definition, enantiomers are non-superimposable mirror images.
If mirror images are superimposable, the molecule is achiral.
(4) Correct Statement: A racemic mixture contains equal amounts of $d$ and $l$ forms.
The optical rotation caused by one isomer is cancelled by the other.
Step 2: Final Answer:
Statement (3) is false because enantiomers must be non-superimposable.