JEE MainChemistryRedox Reactions
In an acidic medium, potassium permanganate reacts with ferrous oxalate ( FeC ₂ O ₄ ). Let x be the change in the oxidation state of manganese per mole of potassium permanganate, and y be the total number of moles of electrons lost per mole of ferrous oxalate. The value of x + y is ________.
Correct answer
8
Step-by-step solution
In an acidic medium, potassium permanganate ( KMnO ₄ ) acts as an oxidizing agent and is reduced to Mn ²⁺ . The initial oxidation state of Mn in KMnO ₄ is +7 . The final oxidation state of Mn is +2 . The change in the oxidation state of manganese, x = |+7 - 2| = 5 . Ferrous oxalate ( FeC ₂ O ₄ ) acts as a reducing agent where both Fe ²⁺ and the oxalate ion ( C ₂ O ₄²⁻ ) undergo oxidation. Oxidation of iron: Fe ²⁺ Fe ³⁺ + 1 e ^- (loss of 1 electron) Oxidation of carbon: C ₂ O ₄²⁻ 2 CO ₂ + 2 e ^- (loss of 2 electrons