Final answer:
HSO4− is the conjugate base of H2SO4 and a conjugate acid when it transforms into SO42−. OH− is a strong base, while H2O can act as a conjugate acid. H2SO4 is an acid in this context.
Step-by-step explanation:
In the Brønsted-Lowry theory of acids and bases, an acid is a substance that donates protons (H+ ions), while a base is a substance that accepts protons. A conjugate base is what remains of the acid after it donates a proton, and a conjugate acid is the species created when the base accepts a proton.
The species HSO4− is the conjugate base of the strong acid H2SO4 (sulfuric acid), and it can also act as the conjugate acid of the SO42− (sulfate ion), a weak base. In water (H2O), it can act as either an acid or a base, depending on the other reactants present. OH− (hydroxide ion) is a strong base that results after H2O donates a proton.
Within the given species, H2SO4 is an acid, OH− is a base, HSO4− is the conjugate base of H2SO4, and it can also be considered a conjugate acid when it donates a proton to become SO42−.