Question #edbe0

1 Answer

Yes. #"AlCl"_3# is a Lewis acid, as it accepts an electron pair into its central empty #3p_z# nonbonding orbital when making a bond, but does not directly donate a proton as a result.

The #"BX"_3# compounds are analogous and also Lewis acids:

Lewis acids just have to accept an electron pair in a reaction to qualify. Brønsted-Lowry acids must donate a proton as a result of that electron acceptance for the Lewis acid to also be a Brønsted acid.

So, many Brønsted acids are also Lewis acids, or contain Lewis acids on them.