Question

Which of the following statement is/are not correct?

• A. A substance which can provide $O{H}^{-}$ in aqueous medium is a base.
• B. A substance which can accept a pair of electron is a base.
• C. A substance which can accept a proton in aqueous medium is a base.
• D. A substance which can donate a pair of electron is a base.

Answer 1

The correct option is B A substance which can accept a pair of electron is a base.

Bronsted - Lowery concept : (Conjugate acid - base concept) (Protonic concept)
Acid: substances which donate H+ are Bronsted Lowery acids (H+ donor)
Base: substances which accept H+ are Bronsted Lowery bases (H+ acceptor)

Lewis concept (electronic concept) :
An acid is a molecule/ion which can accept an electron pair with the formation of a coordinate bond.
A base is any molecule/ion which has a lone pair of electrons that can be donated.