Which is correct statement in the following?

Options

A. `BCl_(3)` and `AlCl_(3)` are both Lewis acids and `BCl_(3)` is a stronger than `AlCl_(3)`.
B. `BCl_(3)` and `AlC l_(3)` are both Lewis acids and `AlCl_(3)` is stronger than `BCl_(3)`.
C. `BCl_(3)` and `AlC_(3)` are equally strong Lewis acids
D. Both `BCl_(3)` and `A lCl_(3)` are not Lewis acids.

Answer

A

Explanation

in `BCl_(3) p pi- p pi` back bonding is less effective than in `AlCl_(3)` because difference in energy levels of p-orbitals or boron (2p) an d of chlorine (3p)