The no. Of moles of KMnO4 that will be needed to react with one mole of sulphite ion in acidic solution is.......

Balance the equations:

Oxidise Sulfite:
_ SO3{2-} + _ H2O = _ SO4{2-} + _ H{+} + _ e{-}

Reduce Permanganate in acid:
_ KMnO4 + _ H{+} + _ e{-} = _ K{+} + _ Mn{2+} + _ H2O

Combine the half equations:
_ KMnO4 + _ H2SO3 = _ K2SO4 + _ MnSO4 + _ H2SO4 + _ H2O

2/5

To determine the number of moles of KMnO4 needed to react with one mole of sulphite ion (SO3^2-) in acidic solution, we need to balance the chemical equation representing the reaction between KMnO4 and sulphite ion.

The balanced equation for this reaction is:

5 SO3^2- + 2 MnO4^- + 6 H+ -> 2 Mn^2+ + 5 SO4^2- + 3 H2O

From this balanced equation, we can see that 2 moles of KMnO4 react with 5 moles of sulphite ion.

Therefore, the ratio between KMnO4 and sulphite ion is 2:5.

So, to calculate the number of moles of KMnO4 needed, we can use the following formula:

Number of moles of KMnO4 = (Number of moles of sulphite ion) * (Ratio of KMnO4 to sulphite ion)

Since we are given that we need to react with one mole of sulphite ion, the calculation is:

Number of moles of KMnO4 = 1 mole * (2 moles KMnO4 / 5 moles sulphite ion)

Number of moles of KMnO4 = 0.4 moles

Therefore, 0.4 moles of KMnO4 would be needed to react with one mole of sulphite ion in acidic solution.