Question

Which two sets of reactants best represents the amphoteric character of $Zn{\left(OH\right)}_2$?
Set I $Zn{\left(OH\right)}_2\left(s\right)$ and $OH\left(aq\right)$
Set II $Zn{\left(OH\right)}_2\left(s\right)$ and $H_{2}O\left(I\right)$
Set III $Zn{\left(OH\right)}_2\left(s\right)$ and $H^{+}\left(aq\right)$
Set IV $Zn{\left(OH\right)}_2\left(s\right)$ and $N{H}_3\left(aq\right)$

• A. III and II
• B. I and III
• C. IV and I
• D. II and IV

Answer 1

The correct option is B I and III

The amphoteric character of $Zn{\left(OH\right)}_2$ is represented by I and III.

$Zn(OH{)}_2+2O{H}^{-}\to Zn{O}_2^{2-}+2H_{2}O$

$Zn(OH{)}_2+2H^{+}\to Z{n}^{2+}+2H_{2}O$