Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Explaining the Question :- To select incorrect statement.

Concept:- This question is based on optical isomerism.

Solution :-

(1) Enantiomers are non-superimposable mirror images and are defined by their ability to rotate planepolarized light in equal but opposite directions, meaning they are always optical isomers of each other.

(2) Diastereoisomers are stereoisomers that are not mirror images. Since they are stereoisomers and not identical, they can be optical isomers if they are chiral (rotate plane-polarized light), and they are not enantiomers, they must be diastereomers. For example, $D$-tartaric acid and meso-tartaric acid are optical isomers and diastereomers.

(3) A compound is chiral (and potentially resolvable) if it is unsymmetrical (lacks a plane or center of symmetry). However, being chiral does not automatically mean it is resolvable at room temperature. For-

e.g.

is chiral but non resolvable.

(4) The presence of a Plane of Symmetry or Center of Symmetry makes a molecule achiral (optically inactive). However, the Alternating Axis of Symmetry is the definitive element of improper rotation/symmetry. If a molecule possesses any ${\mathrm{S}}_{\mathrm{n}}$ axis (even if POS and COS are absent), it is achiral and thus optically inactive. This is a correct statement of the rule.

So, statement (1) (2) and (4) are correct.

Final Answer :- Option (c)