Consider the following equations :
$2 \mathrm{Fe}^{2+}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow x \mathrm{~A}+y \mathrm{~B}$
(in basic medium)
$2 \mathrm{MnO}_{4}^{-}+6 \mathrm{H}^{+}+5 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow x^{\prime} \mathrm{C}+y^{\prime} \mathrm{D}+z^{\prime} \mathrm{E}$
(in acidic medium)
The sum of the stoichiometric coefficients $x, y, x^{\prime}, y^{\prime}$ and $z^{\prime}$ for products A, B, C, D and E, respectively, is ___________.
(11)
$2 \mathrm{Fe}^{2+}+\mathrm{H}_{2} \mathrm{O}_{2} \longrightarrow 2 \mathrm{Fe}^{3+}+2 \mathrm{OH}^{-}$
$2 \mathrm{MnO}_{4}^{-}+6 \mathrm{H}^{+}+5 \mathrm{H}_{2} \mathrm{O}_{2} \longrightarrow 2 \mathrm{Mn}^{2+}+8 \mathrm{H}_{2} \mathrm{O}+5 \mathrm{O}_{2}$
$\because x=2, y=2, x^{\prime}=2, y^{\prime}=8, z^{\prime}=5$
$\therefore x+y+x^{\prime}+y^{\prime}+z^{\prime}=19$