Ncert Exercises & Solutions

Select the correct option based on statements below:

Assertion (A):	Both rhombic and monoclinic sulphur exist as S₈ but oxygen exists as O₂.
Reason (R):	Oxygen forms pπ - pπ multiple bonds due to its small size and small bond length but pπ - pπ bonding is not possible in sulphur.

1.	Both (A) and (R) are true and (R) is the correct explanation of (A).
2.	Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.	(A) is true but (R) is false.
4.	Both (A) and (R) are false.

HINT: Oxygen can form

π

bonds due to its small size but sulphur cannot form.

Explanation:

Both rhombic and monoclinic sulphur exists as S₈ but oxygen exists as O₂, because oxygen forms

pπ - pπ

multiple bonds

due to it's small size and small bond length.

But

pπ - pπ

bonding is not possible in sulphur due to its bigger size as compared to oxygen.

The structures of S₈and O₂ are as follows: