Question

In the reaction between hydrogen sulphide and acidified permanganate solution,

• A. \( \text{H}_2\text{S} \text{ is oxidised to } \text{SO}_2, \text{ MnO}_4^- \text{ is reduced to } \text{MnO}_2 \)
• B. \( \text{H}_2\text{S} \text{ is reduced to } \text{SO}_2, \text{ MnO}_4^- \text{ is oxidised to } \text{Mn}^{2+} \)
• C. \( \text{H}_2\text{S} \text{ is oxidised to } \text{S}, \text{ MnO}_4^- \text{ is reduced to } \text{Mn}^{2+} \)
• D. \( \text{H}_2\text{S} \text{ is reduced to } \text{S}, \text{ MnO}_4^- \text{ is oxidised to } \text{Mn}^{2+} \)

Hint:

In redox reactions, oxidation involves the loss of electrons, while reduction involves the gain of electrons. Always identify the species that gains and loses electrons.

Answer 1

The Correct Option is C

In the reaction between hydrogen sulphide (\( \text{H}_2\text{S} \)) and acidified permanganate solution, the manganese in permanganate \( \text{MnO}_4^- \) is reduced to \( \text{Mn}^{2+} \), and the hydrogen sulphide (\( \text{H}_2\text{S} \)) is oxidised to sulfur (\( \text{S} \)). This is a redox reaction where \( \text{H}_2\text{S} \) undergoes oxidation, and \( \text{MnO}_4^- \) undergoes reduction. Thus, the correct answer is: \[ \text{(3) } \text{H}_2\text{S} \text{ is oxidised to } \text{S}, \text{ MnO}_4^- \text{ is reduced to } \text{Mn}^{2+} \]