Question

Assertion (A): Cold and dilute nitric acid oxidise metals to their nitrates and nitric oxide.

Reason (R): Hot and concentrated nitric acid liberates nitrogen dioxide.

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:

Cold and dilute nitric acid oxidises many metals to form their nitrates, while nitric acid itself is reduced mainly to nitric oxide (NO). Therefore, the Assertion (A) is true.

Hot and concentrated nitric acid generally produces nitrogen dioxide (NO₂) when it reacts with many metals. Therefore, the Reason (R) is also true.

However, the Reason describes the action of hot, concentrated nitric acid and does not explain the action of cold, dilute nitric acid.

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