Which of the following are not amphiprotic in nature?

Options

A. `OH^(-)`
B. `H_(2)PO_(2)^(-)`
C. `HSO_(3)`
D. HF

Answer

To determine which of the following substances are not amphiprotic in nature, we first need to understand what "amphiprotic" means. An amphiprotic substance is one that can both donate and accept a proton (H⁺ ion).

Let's analyze each option step by step:

### Step 1: Understanding Amphiprotic Nature
- **Definition**: An amphiprotic substance can act as both an acid (donating H⁺) and a base (accepting H⁺).

### Step 2: Analyze Each Substance
1. **OH⁻ (Hydroxide Ion)**:
- Can accept a proton (H⁺) to form H₂O.
- Can donate a proton (H⁺) to form O²⁻.
- **Conclusion**: OH⁻ is amphiprotic.

2. **H₂PO₂⁻ (Dihydrogen Phosphite Ion)**:
- Can accept a proton (H⁺) to form H₃PO₂.
- Cannot donate a proton (H⁺) to form HPO₂²⁻.
- **Conclusion**: H₂PO₂⁻ is not amphiprotic.

3. **HSO₃⁻ (Hydrogen Sulfite Ion)**:
- Can accept a proton (H⁺) to form H₂SO₃.
- Can donate a proton (H⁺) to form SO₃²⁻.
- **Conclusion**: HSO₃⁻ is amphiprotic.

4. **HF (Hydrofluoric Acid)**:
- Can donate a proton (H⁺) to form F⁻.
- Cannot accept a proton (H⁺) to form H₂F⁺.
- **Conclusion**: HF is not amphiprotic.

### Step 3: Final Conclusion
Based on the analysis:
- The substances that are **not amphiprotic** are:
- H₂PO₂⁻
- HF

### Answer
The substances that are not amphiprotic in nature are **H₂PO₂⁻ and HF**.

---