How many moles of acidified \(FeSO_4\) can be completely oxidized by one mole of \(KMnO_4\)?

5

The correct answer is option 3. 5.

In acidic media, potassium permanganate \((KMnO_4)\) acts as an oxidizing agent and can oxidize ferrous sulfate \((FeSO_4)\) to ferric sulfate \((Fe_2(SO_4)_3)\). The balanced chemical equation for this reaction is:

\(8H^+ (aq) + 5FeSO_4 (aq) + KMnO_4 (aq) \longrightarrow MnSO_4 (aq) + K_2SO_4 (aq) + 5Fe_2(SO_4)_3 (aq) + 4H_2O (l)\)

From the balanced equation, we can see the following key points:

\(1\) mole of \(KMnO_4\) oxidizes \(5\) moles of \(FeSO_4\).

The oxidation state of iron increases from \(+2\) in \(FeSO_4\) to \(+3\) in \(Fe_2(SO_4)_3\).

Therefore, \(1\) mole of \(KMnO_4\) can completely oxidize \(5\) moles of acidified \(FeSO_4\).