Question

The main factor responsible for weak acidic nature of $B-F$ bonds in $B{F}_3$ is :-

• A. large $EN$ of $F$
• B. $3C-2e^{-}$ bonds in $B{F}_3$
• C. $p\pi -d\pi$ back bonding
• D. $p\pi -p\pi$ back bonding

Answer 1

Answer: (D)

Due to $p\pi -p\pi$ back bonding, the vacant orbital of $B$ accepts a lone pair of $e^{-}$ . Hence, the $B-F$ bonds in $B{F}_3$ becomes weakly acidic.