Chemistry - Stoichiometry Question with Solution | TestHub

${\mathrm{P}}_4+3\mathrm{NaOH}+3{\mathrm{H}}_2\mathrm{O}\to {\mathrm{PH}}_3(\mathrm{g})+3{\mathrm{NaH}}_2{\mathrm{PO}}_2$

$$\begin{array}{rl}4{\mathrm{FeS}}_2+11{\mathrm{O}}_2& \to 2{\mathrm{Fe}}_2{\mathrm{O}}_3+8{\mathrm{SO}}_2(\mathrm{g})\\ 4{\mathrm{H}}_3{\mathrm{PO}}_3& \stackrel{\Delta }{\to }3{\mathrm{H}}_3{\mathrm{PO}}_4+{\mathrm{PH}}_3(\mathrm{g})\\ {\mathrm{ClO}}_3^{-}+5{\mathrm{Cl}}^{-}+6{\mathrm{H}}^{+}& \to 3{\mathrm{Cl}}_2(\mathrm{g})+3{\mathrm{H}}_2\mathrm{O}\end{array}$$