Which compound/s is/are saline hydride?

Options

A. (A) `CaH_(2)`
B. (B) `HCl`
C. (C) `ScH_(2)`
D. (D) `SrH_(2)`

Answer

To determine which compounds are saline hydrides, we need to understand the definition and characteristics of saline hydrides.

### Step-by-Step Solution:

1. **Definition of Saline Hydrides**:
Saline hydrides are compounds formed when hydrogen reacts with S-block elements of the periodic table. These S-block elements include alkali metals (Group 1) and alkaline earth metals (Group 2).

2. **Identify S-block Elements**:
- **Alkali Metals**: Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
- **Alkaline Earth Metals**: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).

3. **Examine the Given Compounds**:
- **Option A: Calcium Hydride (CaH₂)**:
- Calcium is an alkaline earth metal (Group 2). Therefore, calcium hydride is a saline hydride.
- **Option B: Hydrogen Chloride (HCl)**:
- Chlorine is a halogen (Group 17), which is not an S-block element. Thus, HCl is not a saline hydride.
- **Option C: Scandium Hydride (ScH₃)**:
- Scandium is a transition metal (D-block), not an S-block element. Therefore, scandium hydride is not a saline hydride.
- **Option D: Strontium Hydride (SrH₂)**:
- Strontium is also an alkaline earth metal (Group 2). Hence, strontium hydride is a saline hydride.

4. **Conclusion**:
Based on the analysis, the compounds that are saline hydrides are:
- **Option A: Calcium Hydride (CaH₂)**
- **Option D: Strontium Hydride (SrH₂)**

### Final Answer:
The compounds that are saline hydrides are **Calcium Hydride (CaH₂)** and **Strontium Hydride (SrH₂)**.

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