Calcium chloride is used as a dehydrating agent because

Options

A. it has a strong affinity for water
B. it has water of crystalline attached to it
C. it loses water when exposed to air
D. it has a high melting point.

Answer

To solve the question "Calcium chloride is used as a dehydrating agent because," we need to analyze the properties of calcium chloride (CaCl2) and determine the correct reason from the provided options.

### Step-by-Step Solution:

1. **Understanding Calcium Chloride**:
- Calcium chloride (CaCl2) is an inorganic compound that is commonly used in various applications, including as a dehydrating agent.

2. **Definition of Hygroscopic**:
- A hygroscopic substance is one that has the ability to attract and hold water molecules from the surrounding environment.

3. **Properties of Calcium Chloride**:
- Calcium chloride is known to be highly hygroscopic. This means it can absorb moisture from the air or other mixtures effectively.

4. **Reason for Its Hygroscopic Nature**:
- The reason calcium chloride can attract water is due to its strong affinity for water molecules. This strong attraction allows it to pull water out of other substances, making it an effective dehydrating agent.

5. **Evaluating the Options**:
- **Option A**: It has a strong affinity for water. (Correct)
- **Option B**: It has water of crystallization attached to it. (Incorrect, as we are discussing anhydrous calcium chloride)
- **Option C**: It loses water when exposed to air. (Incorrect, it absorbs water instead)
- **Option D**: It has a high melting point. (Incorrect, this does not explain its use as a dehydrating agent)

6. **Conclusion**:
- The correct answer is **Option A**: Calcium chloride is used as a dehydrating agent because it has a strong affinity for water.