The bond dissociation energy of `B-F` in `BF_(3)` is `646 kJ mol^(-1)` whereas that of `C-F` in `CF_(4)` is `515 kJ mol^(-1)`. The correct reason for higher `B-F` bond dissociation energy as compared to that of `C-F` in `CF_(4)` is

Options

A. smaller size B-atom as compared to that of C-atom
B. stronger `sigma` bond between B adn F in `BF_(3)` as compared to that between C and F is `CF_(4)`
C. significant `p pi- p pi` interaction between B and F in `BF_(3)` wheres there is no possibility of such interaction between C and F in `CF_(4)`
D. lower degree of `p pi- p pi` interaction between B and F in `BF_(3)` than that of between C and F in `CF_(4)`

Answer

C

Explanation

In `BF_(3)` there is significant `p pi- p pi` interaction between unshared p-orbital (having no electron) over boron and the lone pair of electron over fluorine in 2p-orbital.