Explain Lewis acid base theory with suitable example. Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base.
a. `OH^(-)` b. `F^(-)` c. `H^(+)` d. `BCl_(3)`

Explanation

`(a)` Hydroxyl ion is a Lewis base as it can donate an electron lone pair `OH^(-)`.
`(b) ` Flouride ion acts as a Lewis base as it can donate any one of its four electron lone pairs.
`(c)` A proton is a Lewis acid as it can accept a lone pair of electrons from bases like hydroxyl ion and fluoride ion.
`(d)` `BCl_(3)` acts as a Lewis acid as it can accept a lone pair of electrons from species like ammonia or amine molecules.