Out of the following, amphiprotic species are :

Options

A. `H_(2)O_(2)^(-)`
B. `HPO_(3)^(2-)`
C. `HCO_(3)^(-)`
D. `CH_(3)CO_(2)^(-)`

Explanation

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

Let's analyze the given options one by one:

1. **H₂O (water)**:
- Water can act as an acid by donating a proton to form OH⁻ (hydroxide ion).
- Water can also act as a base by accepting a proton to form H₃O⁺ (hydronium ion).
- Therefore, H₂O is amphiprotic.

2. **HPO₃²⁻ (hydrogen phosphite ion)**:
- HPO₃²⁻ can donate a proton to form PO₃³⁻ (phosphite ion).
- It can also accept a proton to form H₂PO₃⁻ (dihydrogen phosphite ion).
- Therefore, HPO₃²⁻ is amphiprotic.

3. **HCO₃⁻ (bicarbonate ion)**:
- HCO₃⁻ can donate a proton to form CO₃²⁻ (carbonate ion).
- It can also accept a proton to form H₂CO₃ (carbonic acid).
- Therefore, HCO₃⁻ is amphiprotic.

4. **CH₃COO⁻ (acetate ion)**:
- CH₃COO⁻ can accept a proton to form CH₃COOH (acetic acid).
- However, it cannot donate a proton because the remaining hydrogen atoms are not acidic.
- Therefore, CH₃COO⁻ is not amphiprotic.

### Conclusion:
The amphiprotic species from the given options are:
- H₂O
- HPO₃²⁻
- HCO₃⁻