Question

Assertion (A): Hydrated copper sulphate is an efflorescent salt.

Reason (R): Hydrated copper sulphate absorbs moisture from the atmosphere and dissolves in moisture.

Options

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

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

• If A is true, but R is false.

• If both A and R are false.

Answer 1

If A is true, but R is false.

Explanation:

The assertion is true because hydrated copper sulphate (CuSO₄.5H₂O) is an efflorescent salt, meaning it loses its water of crystallisation when exposed to dry air, turning into a powdery white anhydrous form. The reason is false because efflorescent salts release moisture into the atmosphere rather than absorbing it. The behaviour of absorbing atmospheric moisture to dissolve completely describes a deliquescent substance, not an efflorescent one.