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

Answer

B

Explanation

NOTE: The delocalized `p pi-p pi` bonding between filled p-orbital of F and vacant p-orbital of leads to shortening of `B-F` bond length which results in higher bond dissociation energy of the `B-F` bond.