Question

Assertion (A): V₂O₅ or Pt is used in the catalytic oxidation of sulphur dioxide.

Reason (R): The catalytic oxidation of SO₂ is an exothermic reaction, so it requires to be heated to about 450°C only in the beginning.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Options

• (1)

• (2)

• (3)

• (4)

Answer 1

(2)

Explanation:

Vanadium(V) oxide V₂O₅ or platinum can be used as a catalyst for the oxidation of sulphur dioxide to sulphur trioxide in the Contact process. Therefore, the Assertion (A) is true.

The oxidation of sulphur dioxide to sulphur trioxide is an exothermic reaction, and the reaction mixture is initially heated to about 450°C to start the reaction. Therefore, the Reason (R) is also true.

However, the Reason explains the temperature condition of the reaction, not why V₂O₅ or Pt is used as the catalyst.

Hence, both A and R are true, but R is not the correct explanation of A.