Question

The number of moles of $KMnO_{4}$ that are needed to react completely with one mole of ferrous oxalate in acidic solution is

• A. 3/5
• B. 2/5
• C. 4/5
• D. 1

Answer 1

Answer: (A)

3/5

Answer 2

$Fe^{2 +} + C_{2}O_{4}^{2 -} \rightarrow Fe^{3 +} + 2CO_{2} + 3e^{-}$

$MnO_{4}^{-} + 5e^{-} \rightarrow Mn^{2 +}$

1 mole of $KMnO_{4}$ accepts 5 electrons

1 mole of ferrous oxalate loses 3 electrons

$5e^{-} \equiv 1$ mole of $KMnO_{4}$

$3e^{-}$ will be equivalent to 3/5 mole of $KMnO_{4}$