Chemistry - Redox Reactions Question with Solution | TestHub

$\mathrm{FeS}{\mathrm{O}}_4$ loses 1 ${\mathrm{e}}^{-}$ per mole ($\mathrm{F}{\mathrm{e}}^{2+}$ $\to$ $\mathrm{F}{\mathrm{e}}^{3+}$); $\mathrm{S}{\mathrm{O}}_4^{2-}$ is unaffected. $\mathrm{KMn}{\mathrm{O}}_4$ accepts 5 ${\mathrm{e}}^{-}$ per mole in acid. Moles of $\mathrm{KMn}{\mathrm{O}}_4$ = 1/5. Hence (d).