Hydrogen

(I) H2O2 + O3 H2O + 2O2 (II) H2O2 + Ag2O 2Ag + H2O + O2 Role of hydrogen peroxide in the above reactions is respectively

1. oxidizing in (I) and reducing in (II)
2. reducing in (I) and oxidizing in (II)
3. reducing in (I) and (II)
4. oxidizing in (I) and (II)

Answer

(3) reducing in (I) and (II)

Solution

In both reactions oxygen of H2O2 (oxidation number -1) is converted into O2 (oxidation number 0).

⇒ H2O2 is itself oxidised, i.e. it acts as a reducing agent.

(I) O3 is reduced to O2 and H2O.

(II) Ag+ in Ag2O is reduced to Ag (+1 0).

As per NCERT, H2O2 acts as an oxidising as well as a reducing agent; whenever it gives O2, it is acting as a reducing agent.

∴ H2O2 is reducing in (I) and (II).

Answer: (3)