Match the following : List - I List - II (P) (1) Conformation with minimum vander-waal strain (Q) (2) Conformation with maximum vander-wall stain (R) (3) Conformation of maximum torsional strain (S) (

Question

Match the following : List - I List - II (P) (1) Conformation with minimum vander-waal strain (Q) (2) Conformation with maximum vander-wall stain (R) (3) Conformation of maximum torsional strain (S) (4) Conformation with minimum torsional strain

TestHub · Accepted Answer

Question Explanation:

Match the Newman projections of butane with their characteristic strains.

Concept:

Strains in Molecular Conformations.

Solution:

Conformations of butane ( $CH_{3} - CH_{2} - CH_{2} - CH_{3})$ vary in stability based on strain:

(P) Partially Eclipsed: Bulky methyl groups are near hydrogens. Result: High torsional strain (3).

(Q) Fully Eclipsed: Bulky methyl groups are directly over each other. Result: Maximum van der

Waals strain (2).

(R) Anti: Methyl groups are 180° apart. Result: Minimum van der Waals strain (1).

(S) Gauche: Methyl groups are 60° apart. Result: Minimum torsional strain (4) among staggered

types (though anti is lower).

Final Answer: Option (B)

Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Options:

Doubts & Discussion

List - I	List - II
(P)	(1) Conformation with minimum vander-waal strain
(Q)	(2) Conformation with maximum vander-wall stain
(R)	(3) Conformation of maximum torsional strain
(S)	(4) Conformation with minimum torsional strain