Which of the following can give base `OH^(-)`

Options

A. `H_(2)O`
B. `H_(3)O^(+)`
C. `H_(2)`
D. HCl

Explanation

To determine which of the given options can produce the hydroxide ion (OH⁻), we can analyze the behavior of each compound in water and their ability to donate OH⁻ ions.

### Step-by-Step Solution:

1. **Understanding Hydroxide Ion (OH⁻)**:
- Hydroxide ions are produced when a base dissociates in water. A base is typically a substance that can accept protons (H⁺) or donate hydroxide ions.

2. **Analyzing Water (H₂O)**:
- Water can act as both an acid and a base. When water dissociates, it can produce hydroxide ions:
\[ H_2O \rightleftharpoons H^+ + OH^- \]
- Therefore, water can give OH⁻ ions.

3. **Analyzing Other Compounds**:
- **HCl**: Hydrochloric acid dissociates in water to produce H⁺ and Cl⁻:
\[ HCl \rightarrow H^+ + Cl^- \]
- It does not produce OH⁻ ions; instead, it increases the concentration of H⁺ ions.

- **H₂**: Hydrogen gas does not dissociate to produce hydroxide ions. It remains as H₂ in the gaseous state and does not interact with water to yield OH⁻.

- **Cl⁻**: Chloride ions do not produce hydroxide ions when dissolved in water. They are the conjugate base of a strong acid (HCl) and do not exhibit basic properties.

4. **Conclusion**:
- The only option that can produce hydroxide ions (OH⁻) is water (H₂O). Therefore, the answer is **H₂O**.

### Final Answer:
The compound that can give base OH⁻ is **H₂O**.