Question

The number of moles of KMnO₄ that will be needed to react with one mole of sulphide ion in acidic solution is ______.

Options

• `2/5`

• `3/5`

• `4/5`

• 1

Answer 1

The number of moles of KMnO₄ that will be needed to react with one mole of sulphide ion in acidic solution is `bbunderline(2/5)`.

Explanation:

In an acidic medium, potassium permanganate (KMnO₄) acts as a strong oxidising agent. It oxidises the sulphide ion \[\ce{(S^-_2)}\] to sulphur. The balanced ionic equation is:

\[\ce{2MnO^-_4 + 5S^{2-} + 16H+ -> 2Mn^{2+} + 5S + 8H2O}\]

From the equation, 2 moles of KMnO4 react with 5 moles of \[\ce{S^{2-}}\]

So, for 1 mole of \[\ce{S^{2-}}\]:

Required moles of KMnO₄ = `2/5`