The figure given below demonstrates the preparation of oxygen.

2KClO₃ (s) $\xrightarrow{\text{MnO}{_2}/{\text {heat}}}$ 2KCl (s) + 3O₂ (g)

(I) Which of the following statements is/are correct about the reaction?

1. It is a decomposition reaction and is exothermic.

2. It is a decomposition reaction and is endothermic.

3. It is a photochemical decomposition reaction.

4. It is a combination reaction.

(II) Potassium chlorate is:

1. an oxidising agent.

2. a reducing agent.

3. both reducing as well as an oxidising agent.

4. all options are correct.

(III) In the reaction, manganese dioxide:

1. takes part in the reaction.

2. acts as a catalyst.

3. decreases the speed of reaction.

4. helps in producing more oxygen.

(I) It is a decomposition reaction and is endothermic.

Reason — When potassium chlorate (2KClO₃) is heated in the presence of manganese dioxide it will undergo decomposition reaction. Since heat is absorbed during the process it is a endothermic reaction.

(II) an oxidising agent

Reason — Potassium chlorate (KClO₃) provides oxygen, which supports oxidation of other substances. It releases oxygen, hence it can oxidize other materials.

(III) acts as a catalyst.

Reason — Potassium chlorate decomposes only at 700°C and even then the rate of release of oxygen is very slow. But when potassium chlorate is heated in the presence of manganese dioxide, decomposition begins at a much lower temperature, 300°C and manganese dioxide remains unaffected. Thus, in this reaction, manganese dioxide acts as a catalyst