Which of the following can be used to prevent the decomposition of H₂ O₂ ?

Solution

Chemistry ma’am · 4 steps

Hydrogen peroxide slowly breaks down on standing, and a pinch of urea is the stabiliser that slows it down.

1. Why it decomposes. H₂O₂ breaks down on its own: 2H₂O₂ → 2H₂O + O₂. Light, traces of metal ions, alkali and rough surfaces such as dust all speed this up.
2. How it is stored. It is kept in wax-lined glass or plastic bottles, away from light. A small amount of urea is added as a stabiliser.
3. Role of urea. Urea acts as a negative catalyst (an inhibitor). It slows the decomposition without being used up as an oxidising or reducing partner of H₂O₂.
4. So. Urea, option (a), is used to prevent the decomposition of H₂O₂. The other three are organic reducing agents that H₂O₂ can oxidise, so they would use it up instead of keeping it.

The idea to keep. Store H₂O₂ in the dark, in wax-lined bottles, with a little urea as a negative catalyst. A stabiliser must slow the breakdown, not react with the peroxide.

Answer from the NTA final answer key. Solution by PrepWiser.