The Hydrogen Sulfate or Bisulfate Ion HSO₄^- Can Act as Either

Multiple Choice

The hydrogen sulfate or bisulfate ion HSO₄^- can act as either an acid or a base in water solution. In which of the following equations does HSO₄^- act as an acid?

A) HSO₄^- + H₂O → SO₄^2- + H₃O⁺
B) HSO₄^- + H₂O → H₂SO₄ + OH^-
C) HSO₄^- + H₃O⁺ → SO₃ + 2H₂O
D) HSO₄^- + OH^- → H₂SO₄ + O^2-
E) none of these