Which of the following compounds is amphoteric in nature?
Which of the following compounds is amphoteric in nature?
HCl
$\mathrm{H}_2 \mathrm{O}$
$\mathrm{CH}_3 \mathrm{COOH}$
NaOH
Solution
Water can act as an acid as well as a base. Therefore, it is amphoteric.
$\begin{aligned}
& \text { E.g. } \underset{(\text { Acid })}{\mathrm{H}_2 \mathrm{O}_{(l)}}+\mathrm{NH}_{3(\mathrm{aq})} \rightleftharpoons \mathrm{OH}_{(\mathrm{aq})}^{-}+\mathrm{NH}_{4(\mathrm{aq})}^{+} \\
& \underset{\text { (Base) }}{\mathrm{H}_2 \mathrm{O}_{(l)}}+\mathrm{HCl}_{\text {(aq) })} \rightleftharpoons \mathrm{H}_3 \mathrm{O}_{(\mathrm{aq})}^{+}+\mathrm{Cl}_{(\mathrm{aq})}^{-}
\end{aligned}$