One mole of KMnO ₄ oxidizes x moles of I ^- in an acidic medium. In a faintly alkaline medium, one mole of KMnO ₄ oxidizes y moles of I ^- . The value of the ratio x y is:

Step-by-step solution

In an acidic medium, MnO ₄^- is reduced to Mn ²⁺ (change in oxidation state = 5 ), and I ^- is oxidized to I ₂ (change in oxidation state = 1 per I ^- atom). Equating equivalents: 1 5 = x 1 x = 5 . In a faintly alkaline medium, MnO ₄^- is reduced to MnO ₂ (change in oxidation state = 3 ), and I ^- is oxidized to IO ₃^- (change in oxidation state = 6 per I ^- atom). Equating equivalents: 1 3 = y 6 y = 0.5 . The ratio is x y = 5 0.5 = 10 . Answer: 10