Question

Hybridisation of central atom does not always change due to back bonding". This statement is
valid for which of the following compounds?
(i) CCL3-
(ii) CCI2
(iii) CF2
(iv) N(SiH3)3
(1) (i), (ii)
(2) (i), (iii)
(3) (ii), (iii).
(4) All
​

Answer 1

The given statement is valid for option (ii) and (iii). Hence, third option is the correct answer.

• Backbonding is not a true bond. However, in some cases, its presence alters the hybridization of the central atom. For e.g., on seeing the molecular formula of option (iv), i.e. N(SiH₃)₃ one might expect it to be sp³ hybridized like NH₃ molecule. But, in reality, it is sp² hybridized because of the back donation of the lone pair of nitrogen to the vacant d-orbital of Si.
• CCl₂ and CF₂ are carbenes and retain the same hybridization even after backbonding.