Question

Assertion : `PF_(5),SF_(6)and H_(2)SO_(4)` are the examples of expanded octet molecules .
Reason : Octet rule is not applicable to the second period elements of the periodic table.
A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason in not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer 1

Correct Answer - C
In `PF_(5), SF_(6) and H_(2)SO_(4)`, the central atom has more than eight valence electrons hence they exhibit expanded octet. This is possible due to availability of 3d orbitals.
Elements in and behond the third period of the periodic table do not follow octet rule thus it applies mainly to the second period elements of the periodic table.