Among the statements (a) - (d), the correct ones are :
(a) Decomposition of hydrogen peroxide gives dioxygen.
(b) Like hydrogen peroxide, compounds, such as KCIO₃, Pb(NO₃)₂ and NaNO₃ when heated liberate dioxygen.
(c) 2-Ethylanthraquinone is useful for the industrial preparation of hydrogen peroxide.
(d) Hydrogen peroxide is used for the manufacture of sodium perborate.

Solution

Chemistry ma’am · 2 steps

Test each statement on its own: all four are standard facts about H₂O₂, so every one stays in.

1. Judge each statement. Check every statement separately against what you know about H₂O₂. Only then match the true ones to an option.

   Statement	What actually happens	Verdict
   (a) H₂O₂ decomposes to O₂	2H₂O₂ → 2H₂O + O₂	True
   (b) Salts that give O₂ on heating	2KClO₃ →(Δ) 2KCl + 3O₂, 2Pb(NO₃)₂ →(Δ) 2PbO + 4NO₂ + O₂, 2NaNO₃ →(Δ) 2NaNO₂ + O₂	True
   (c) 2-Ethylanthraquinone process	Air oxidises 2-ethylanthraquinol to give H₂O₂ and 2-ethylanthraquinone. H₂ over Pd reduces the quinone back, so the cycle repeats.	True
   (d) Sodium perborate	H₂O₂ is used to make sodium perborate, a bleach in washing powders	True

2. So. All four statements are correct, so the answer is option (a): (a), (b), (c) and (d).

The idea to keep. Judge each statement alone before you look at the options. For H₂O₂, remember: it releases O₂, it is made by the anthraquinone process, and it is used to make perborate.

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