Among the following which islare interstitial hydride ?

Options

A. `LaH_(3)`
B. `CaH_(2)`
C. `NaH`
D. HF

Answer

To determine which of the given compounds is an interstitial hydride, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Hydrides**:
- Hydrides can be classified into three main categories: ionic (saline) hydrides, molecular hydrides, and metallic (interstitial) hydrides.
- Ionic hydrides are typically formed by alkali and alkaline earth metals (Group 1 and Group 2).
- Molecular hydrides are formed by non-metals (Group 13 to Group 17).
- Metallic hydrides (interstitial hydrides) are formed by transition metals and some lanthanides and actinides.

2. **Analyze the Given Options**:
- The options provided are:
1. Lanthanum hydride (LaH₃)
2. Calcium hydride (CaH₂)
3. Sodium hydride (NaH)
4. Hydrogen chloride (HCl)

3. **Evaluate Each Option**:
- **Lanthanum Hydride (LaH₃)**:
- Lanthanum is an F-block element. F-block elements can form interstitial hydrides. Thus, LaH₃ is an interstitial hydride.
- **Calcium Hydride (CaH₂)**:
- Calcium is in Group 2 and forms ionic hydrides. Therefore, CaH₂ is not an interstitial hydride.
- **Sodium Hydride (NaH)**:
- Sodium is in Group 1 and also forms ionic hydrides. Hence, NaH is not an interstitial hydride.
- **Hydrogen Chloride (HCl)**:
- HCl is a molecular hydride formed from a non-metal (chlorine). Thus, HCl is not an interstitial hydride.

4. **Conclusion**:
- Based on the analysis, the only interstitial hydride among the options is **Lanthanum Hydride (LaH₃)**.

### Final Answer:
The interstitial hydride among the given options is **Lanthanum Hydride (LaH₃)**.

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