Which one of the following is amphiprotic in nature?

Options

A. `F^-`
B. `HPO_4^(2-)`
C. `PO_4^(2-)`
D. `Cl^-`

Explanation

To determine which of the given species is amphiprotic, we need to understand the definition of amphiprotic substances. An amphiprotic substance is one that can both donate and accept a proton (H⁺ ion).

**Step-by-Step Solution:**

1. **Identify the Given Species:**
The options provided are:
- F⁻ (fluoride ion)
- HPO₄²⁻ (hydrogen phosphate ion)
- PO₄²⁻ (phosphate ion)
- Cl⁻ (chloride ion)

2. **Understand the Concept of Amphiprotic:**
An amphiprotic species can act as both an acid (donating a proton) and a base (accepting a proton).

3. **Analyze Each Species:**
- **F⁻ (Fluoride Ion):**
- Can it donate a proton? No, it does not have a hydrogen atom to donate.
- Can it accept a proton? Yes, it can accept a proton to form HF (hydrofluoric acid).
- Conclusion: Not amphiprotic.

- **HPO₄²⁻ (Hydrogen Phosphate Ion):**
- Can it donate a proton? Yes, it can donate a proton to form PO₄³⁻ (phosphate ion).
- Can it accept a proton? Yes, it can accept a proton to form H₂PO₄⁻ (dihydrogen phosphate ion).
- Conclusion: This species is amphiprotic.

- **PO₄²⁻ (Phosphate Ion):**
- Can it donate a proton? No, it does not have a hydrogen atom to donate.
- Can it accept a proton? Yes, it can accept a proton to form HPO₄²⁻.
- Conclusion: Not amphiprotic.

- **Cl⁻ (Chloride Ion):**
- Can it donate a proton? No, it does not have a hydrogen atom to donate.
- Can it accept a proton? Yes, it can accept a proton to form HCl (hydrochloric acid).
- Conclusion: Not amphiprotic.

4. **Final Conclusion:**
The only species that can both donate and accept a proton is **HPO₄²⁻ (hydrogen phosphate ion)**. Therefore, it is the amphiprotic species among the given options.

**Final Answer: HPO₄²⁻ (Hydrogen Phosphate Ion)**

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