Question

In the reaction, $Fe{S}_2+KMn{O}_4+H^{+}\to F{e}^{3+}+S{O}_2+M{n}^{2+}+H_{2}O$, the equivalent mass of $Fe{S}_2$ would be equal to___________.

• A. $\text{molar mass}$
• B. $\frac{\text{molar mass}}{10}$
• C. $\frac{\text{molar mass}}{11}$
• D. $\frac{\text{molar mass}}{13}$

Answer 1

The correct option is C $\frac{\text{molar mass}}{11}$

$F{e}^{2+}\to F{e}^{3+}+e^{-};S_2^{2-}\to 2S^{4+}+10e^{-}$
$\therefore Fe{S}_2\to 2S^{4+}+F{e}^{3+}+11e^{-}$
Equivalent mass of $Fe{S}_2=\frac{\text{Molar mass}}{11}$.