An example of non-stoichiometric hydride is

The following reactions show the ${\mathrm{H}}_2{\mathrm{O}}_2$ behaviour in $\mathrm{I}$ and$\mathrm{II}$ reactions as:
$\begin{array}{l}\text{ I. }\mathrm{PbS}\left(\mathrm{s}\right)+4{\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{aq}\right)⟶{\mathrm{PbSO}}_4\left(\mathrm{s}\right)+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\end{array}$

$\mathrm{II}. \mathrm{HOCl}+{\mathrm{H}}_2{\mathrm{O}}_2⟶{\mathrm{H}}_3{\mathrm{O}}^{+}+{\mathrm{Cl}}^{-}+{\mathrm{O}}_2$