Ionic hydrides are usually

Options

A. Good conductors of electricity in solid state
B. Stoichiometric compounds
C. Volatile
D. Non-crystalline

Answer

To determine the correct statement about ionic hydrides, let's analyze the properties of ionic hydrides step by step.

### Step-by-Step Solution:

1. **Understanding Ionic Hydrides**:
Ionic hydrides are compounds formed between hydrogen and more electropositive metals. They typically exhibit properties similar to those of ionic compounds.

2. **Evaluating the Options**:
- **Option 1: Good conductor of electricity in solid state**:
Ionic compounds, including ionic hydrides, do not conduct electricity in the solid state because the ions are fixed in place within the crystal lattice. They can only conduct electricity when melted or dissolved in water.

- **Option 2: Stoichiometric compounds**:
Ionic hydrides are indeed stoichiometric compounds, meaning they have a fixed ratio of elements. For example, sodium hydride (NaH) has a 1:1 ratio of sodium to hydrogen.

- **Option 3: Volatile**:
Ionic hydrides are generally non-volatile. They do not easily evaporate and remain stable at room temperature.

- **Option 4: Non-crystalline**:
Ionic hydrides are typically crystalline in nature. They form a well-defined crystal lattice structure.

3. **Conclusion**:
Based on the evaluation of the options, the correct statement about ionic hydrides is that they are **stoichiometric compounds**. Therefore, the answer is **Option 2**.

### Final Answer:
Ionic hydrides are usually **stoichiometric compounds**.

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