Question

Which of the following species is amphoteric in nature?

Options

• \[\ce{HCl}\]

• \[\ce{H2O}\]

• \[\ce{CH3COOH}\]

• \[\ce{NaOH}\]

Answer 1

\[\ce{H2O}\]

Explanation:

Water is amphoteric in nature i.e. it can acts as an acid as well as a base.

It acts as an acid with NH₃ and a base with H₂S.

\[\ce{H2O + NH3 <=> OH- + NH^+_4}\]

\[\ce{H2O + H2S <=> H3O+ + HS-}\]

The auto protolysis (self ionisation) of water takes place as follows

\[\ce{\underset{Acid}{H2O} + \underset{Base}{H2O} <=> H3O+ + OH-}\]