Answer: Acidified KMnO 4 (a stronger oxidising agent).
- A Acidified KMnO<sub>4</sub> (a stronger oxidising agent)
- B Iodide ion, which it oxidises to free iodine
- C Fe<sup>2+</sup>, which it oxidises to Fe<sup>3+</sup>
- D Cl<sub>2</sub> gas, which it reduces to chloride ion
Correct answer: A. Acidified KMnO<sub>4</sub> (a stronger oxidising agent)
Explanation: When a stronger oxidant like acidified KMnO<sub>4</sub> reacts with H<sub>2</sub>O<sub>2</sub>, H<sub>2</sub>O<sub>2</sub> reduces MnO<sub>4</sub><sup>-</sup> by donating electrons: 2KMnO<sub>4</sub> + 5H<sub>2</sub>O<sub>2</sub> + 3H<sub>2</sub>SO<sub>4</sub> → 2MnSO<sub>4</sub> + 5O<sub>2</sub> + K<sub>2</sub>SO<sub>4</sub> + 8H<sub>2</sub>O.
Each water molecule's O-H bonds (covalent, solid) can hydrogen-bond (dashed) to neighbouring molecules, forming an extended network responsible for water's unusually high boiling point and density anomaly.
Concept context
The simplest and most abundant element in the universe. Study its unique position in the periodic table, isotopes (protium, deuterium, tritium), properties of water and hydrogen peroxide, and industrial uses.