The tendency of BF_3, BCl_3 and BBr_3 to behave as Lewis acid decrease

1.	The tendency of BF_3, BCl_3 and BBr_3 to behave as Lewis acid decreases in the sequence:
Answer» `BCl_3 GT BF_3 gt BBr_3` `BBr_3 gt BCl_3 gt BF_3` `BBr_3 gt BF_3 gt BCl_3` `BF_3 gt BCl_3 gt BBr_3` Solution :p-p overlap between B and F is maximum due to identical SIZE and energy of p-orbitals, so electron deficiency in BORON of `BF_3` is neutralized partially to the maximum extent by BACK DONATION. Hence `BF_3` is least acidic.

Discussion