Correct Answer: Hygroscopic
Explanation:
- Drying agents are substances that remove moisture from other substances or from the air.
- They work because they are hygroscopic, meaning they readily absorb water vapour from their surroundings.
- Examples include concentrated sulfuric acid (H₂SO₄), quicklime (CaO), and anhydrous calcium chloride (CaCl₂).
- The other options do not fit:
- Amphoteric: means a substance can act as both acid and base.
- Acidic: not necessarily a property for drying agents.
- Efflorescent: means losing water of crystallization, the opposite of absorbing moisture.
Thus, drying agents are generally hygroscopic substances.
