Q55 / 180 · KCET 2015 · Chemistry

The correct statement is

A
\( \mathrm{BF}_{3} \) is the strongest Lewis acid among the other boron halides.
B
\( \mathrm{BI}_{3} \) is the weakest Lewis acid among the boron halides.
Correct answer
C
There is maximum \( p \Pi-p_{\Pi} \) back bonding in \( B F_{3} \)
D
There is minimum \( p_{\Pi}-p_{I} \) back bonding in \( B F_{3} \)

Solution

There is maximum \( p \pi-p \pi \) back bonding in \( B F_{3} \) due to identical size of \( 2 p^{-} \)orbitals of \( B \) and \( F \)

Hence, the correct answer is option: 'C'.