AIIMS 2019 Chemistry Oxidation of Iron Compounds MCQ Question

To oxidize the given compounds in acidic medium, we need to consider the oxidation states and the number of moles of electrons transferred during the reactions. Each mole of FeC₂O₄ (oxalic acid) can donate 2 moles of electrons, Fe₂(C₂O₄)₃ donates 6 moles, FeSO₄ donates 1 mole, and Fe₂(SO₄)₃ donates 6 moles, totaling 15 moles of electrons. Since KMnO₄ in acidic medium requires 5 moles of electrons per mole to be reduced from MnO₄⁻ to Mn²⁺, the total moles of KMnO₄ required is 15/5 = 3, making option A (2 moles) incorrect. The confusion arises from miscalculating the total moles of electrons or the stoichiometry involved in the reactions.