Question

Assertion (A): The yellow colour of nitric acid is removed by using carbon dioxide gas or dry air.

Reason (R): Carbon dioxide gas or dry air drives away NO₂ gas from the warm nitric acid.

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

(1)

Explanation:

The yellow colour of nitric acid is due to dissolved nitrogen dioxide (NO₂). Passing carbon dioxide gas or dry air through the warm acid removes this dissolved NO₂. Therefore, the Assertion (A) is true.

Carbon dioxide gas or dry air drives out dissolved nitrogen dioxide from warm nitric acid, removing the yellow colour. Therefore, the Reason (R) is true and correctly explains the Assertion.

Hence, both A and R are true, and R is the correct explanation of A.