The starting material for convenient preparation of deuterated hydrogen peroxide (D₂O₂) in :

Solution

Chemistry ma’am · 3 steps

Pick a solid that already has an O–O bond and lets heavy water supply every hydrogen.

1. What D2O2 needs. D₂O₂ needs a peroxide link, O–O, with deuterium on both oxygens. So the convenient route starts from a peroxide-containing compound and reacts it with D₂O, so that no ordinary hydrogen enters.
2. Peroxodisulphate works. Potassium peroxodisulphate, K₂S₂O₈, contains an O–O bridge between its two sulphur atoms. Heavy water hydrolyses it and that bridge becomes D₂O₂. This is the method NCERT gives for preparing D₂O₂ in the laboratory.

   K₂S₂O₈(s) + 2D₂O(l) → 2KDSO₄(aq) + D₂O₂(l)

3. So. The starting material is K₂S₂O₈, option (d).

The idea to keep. For a deuterated compound, use heavy water as the only hydrogen source. For D₂O₂, learn the pair: K₂S₂O₈ hydrolysed by D₂O.

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