Question

The bond dissociation energy of $B - F$ in $BF_3$ is $646\,kJ\, mol^{−1}$ whereas that of $C-F$ in $CF_4$ is $515kJ mol^{−1}$ . The correct reason for higher $B-F$ bond dissociation energy as compared to that of $C- F$ is :

• A. smaller size of B-atom as compared to that of C- atom
• B. stronger $σ$ bond between B and F in 3 BF as compared to that between C and F in $CF_4$
• C. significant $pπ - pπ$ interaction between $B$ and $F$ in $BF_3$ whereas there is no possibility of such interaction between C and F in $CF_4$
• D. lower degree of $pπ - pπ$ interaction between $B$ and $F$ in $BF_3$ than that between C and F in $CF_4$

Answer 1

Answer: (C)

option itself is the reason