Question

Octet rule is not violated in case of:

• A. methane
• B. boron trifluoride
• C. sulphur hexafluoride
• D. aluminium chloride

Answer 1

Answer: (A)

methane

In boron trifluoride, boron has three electrons in its outermost orbit and it forms three covalent bonds with three fluorines. Total electrons in its outermost shell become 3+3 = 6. So, it violates octet rule.

In sulphur hexafluoride, Sulphur has 6 electrons in its outermost orbit and it forms 6 covalent bonds with six fluorine. Total electrons in its outermost shell become 6+6 = 12. So, it violates octet rule.

In aluminium chloride, aluminium has three electrons in its outermost orbit and it forms three covalent bonds with three chlorines. Total electrons in its outermost shell become 3+3 = 6. So, it violates octet rule.

In methane, carbon has 4 electrons in its outermost orbit and it forms 4 covalent bonds with three hydrogens. Total electrons in its outermost shell become 4+4 = 6. So, it does not violate octet rule.

So, the correct answer is option $A$.