Question

Among the boron halides, which is the strongest lewis acid?

• A. $BB{r}_3$
• B. $BC{l}_3$
• C. $B{I}_3$
• D. $B{F}_3$

Answer 1

The correct option is C

$B{I}_3$

In $B{F}_3$ and $BC{l}_3$, strong back bonding takes place. Hence they are weakest lewis acids. Rest are checked according to the extent of back bonding (in comparison).