Question

Classify the following species as Lewis acids and Lewis bases and show how these act as such : `(a) HO^(-) (b) F^(-) (c) H^(+) (d) BCl_(3)`

Answer 1

(a) : `OH^(-)` (hydroxyl ion ) is a Lewis base as it can donate an electron pair.
(b) `:underset(..)overset(..)(F):^(-)` is a Lewis base as it has 4 lone pairs of electrons and can donate any one of these.
(c) `H^(+)` is a Lewis base as it can accept electron pair from bases like `OH^(-), F^(-) ` ion etc.
(d) `BCl_(3) ` is a Lewis acid as B is electron deficient (having only 6 electrons instead of complete octet). Hence, it can accept an electron pair from species like ammonia, amines etc.