Which of the following species is amphiprotic within an aqueous solvent? 

• A. Br^–
• B. HC₂H₃O₂
• C. SO₄^2–
• D. HSe^–
• E. H₃O⁺

Answer: (D)

Verified step by step guidance

1. Understand the definition of an amphiprotic species: it is a species that can both donate and accept a proton (H\(\textsuperscript{+}\)) in an aqueous solution.
2. Analyze each species to determine if it can act as both an acid (proton donor) and a base (proton acceptor):
3. a) Br\(\textsuperscript{–}\) is the conjugate base of HBr and typically only accepts protons, so it is not amphiprotic.
4. b) HC\_2H\_3O\_2 (acetic acid) can donate a proton but does not accept one, so it is not amphiprotic.
5. c) SO\_4\(\textsuperscript{2–}\) can accept protons to form HSO\_4\(\textsuperscript{–}\) but generally does not donate protons, so it is not amphiprotic.
6. d) HSe\(\textsuperscript{–}\) can both donate a proton to form Se\(\textsuperscript{2–}\) and accept a proton to form H\_2Se, making it amphiprotic.
7. e) H\_3O\(\textsuperscript{+}\) is a proton donor only (acidic), so it is not amphiprotic.