The number of moles KMnO ₄ that will be needed to react with one mole of sulphite ion in acidic solution is:

Step-by-step solution

The balanced chemical equation is: 2 MnO ₄⁻+ 6 H ⁺+5 SO ₃⁻⁻ 2 Mn ⁺⁺+5 SO ₄⁻⁻+3 H ₂ O From the equation it is clear that Moles of MnO ₄⁻ require to oxidise 5 moles of SO ₃⁻⁻ are 2 Moles of MnO ₄⁻ require to oxidise 1 mole of SO ₃⁻⁻ are 2 / 5 .