Which gas should not be collected over water because of its high solubility in water ?

Options

A. `H_(2)`
B. `N_(2)`
C. `CH_(4)`
D. `HCl`

Explanation

To determine which gas should not be collected over water due to its high solubility, we can analyze the properties of various gases in relation to water.

### Step-by-Step Solution:

1. **Understand the Concept of Solubility**:
- Water is a polar solvent, which means it can dissolve other polar substances effectively. The principle of "like dissolves like" applies here, indicating that polar substances will dissolve in polar solvents.

2. **Identify the Gases**:
- The question implies that we need to consider various gases and their solubility in water. Common gases to consider include HCl, H2, N2, and CH4.

3. **Analyze Each Gas**:
- **H2 (Hydrogen)**: This is a non-polar molecule and has low solubility in water.
- **N2 (Nitrogen)**: This is also a non-polar molecule and has low solubility in water.
- **CH4 (Methane)**: This is another non-polar molecule and has low solubility in water.
- **HCl (Hydrochloric Acid)**: This is a polar molecule and is highly soluble in water due to its ability to ionize into H⁺ and Cl⁻ ions.

4. **Conclusion**:
- Among the gases analyzed, HCl is the only gas that is highly soluble in water. Therefore, it should not be collected over water because it will dissolve rather than be collected as a gas.

5. **Final Answer**:
- The gas that should not be collected over water due to its high solubility is **HCl**.