Question

Write chemical reactions to show the amphoteric nature of water.

Answer 1

Amphoteric nature of water is represented by following chemical reactions.
(1) Water as a base:
$H_{2}O\left(l\right)+H_{2}S\left(g\right)\rightleftharpoons H_3{O}^{+}\left(aq\right)+H{S}^{-}\left(aq\right)$
(2) Water as an acid:
$H_{2}O\left(l\right)+N{H}_3\left(aq\right)\rightleftharpoons O{H}^{-}+N{H}_4^{+}$
(3) Self ionization of water in which water simultaneous acts as acid and base.
$2H_{2}O\to H_3{O}^{+}+O{H}^{-}$