Among the following, which is the strongest Lewis acid?

Question

Among the following, which is the strongest Lewis acid? (A) BF3 (B) BCl3 (C) BBr3 (D) BI3

Tardigrade Admin · Accepted Answer

The strengths of boron halides as Lewis acids are in the order

BI_{3} > BBr_{3} > BCl_{3} > BF_{3}

. This order is the opposite of what is expected on steric grounds as well as from considerations of electronegatively. It can be explained in terms of boron-halogen-bonding.
Here, acidic nature

\propto \frac{1}{e x t e n t o f ba c kb o n d in g}

Q. Among the following, which is the strongest Lewis acid?

$B F_{3}$

$BC l_{3}$

$BB r_{3}$

$B I_{3}$

Q. Among the following, which is the strongest Lewis acid?

BF3​

BCl3​

BBr3​

BI3​

$B F_{3}$

$BC l_{3}$

$BB r_{3}$

$B I_{3}$