An ionic compound that attracts atmospheric water so strongly that
a hydrate is formed is said to be :

Options

A. Dilute
B. Hygroscopic
C. Immiscible
D. Miscible

Explanation

To solve the question, we need to identify the term used to describe an ionic compound that attracts atmospheric water strongly enough to form a hydrate.

### Step-by-Step Solution:

1. **Understanding Hydrates**:
- A hydrate is a compound that contains water molecules within its structure. These water molecules can be loosely or tightly bound to the ionic compound.

2. **Identifying Ionic Compounds**:
- Ionic compounds are formed from the electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions). Some ionic compounds have a strong affinity for water.

3. **Defining Hygroscopic Compounds**:
- Compounds that can attract and hold water molecules from the surrounding environment are referred to as hygroscopic. This property allows them to absorb moisture and potentially form hydrates.

4. **Examples of Hygroscopic Compounds**:
- Common examples include anhydrous copper(II) sulfate (CuSO4), quicklime (CaO), and anhydrous sodium carbonate (Na2CO3). These compounds can absorb water vapor from the atmosphere and form hydrates.

5. **Conclusion**:
- Therefore, an ionic compound that attracts atmospheric water so strongly that a hydrate is formed is said to be **hygroscopic**.

### Final Answer:
The answer is **hygroscopic**.

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