Question

How many moles of $KMn{O}_4$ are reacted with one mole of ferrous oxalate in an acidic medium?

• A. $\frac{2}{5}$
• B. $\frac{1}{5}$
• C. $\frac{3}{5}$
• D. $\frac{5}{3}$

Answer 1

The correct option is C $\frac{3}{5}$

$2KMn{O}_4+5C_2{O}_4^{2-}+16H^{+}\to 2M{n}^{2+}+2K^{+}+10C{O}_2+8H_{2}O$
$KMnO4+5F{e}^{2+}+8H^{+}\to K^{+}+5F{e}^{3+}+M{n}^{2+}+4H_{2}O$

From the above equations, it is observed that 3 moles of $KMnO4$ will be needed to react completely with five moles of ferrous oxalate in acidic solution.
No. Of equivalents of $KMnO4=$no. Of equivalents of $Fe{C}_2{O}_4$
Equiv. Of$KMn{O}_4=n\times no.Ofmoles=5\times x.$
Equivalents of $Fe{C}_2{O}_4=3\times 1=3$
$5x=3$
$x=3/5$