Answer
First pair: $HS{O_4}^-$: Base; $H_2SO_4$: Conjugate acid.
Second pair: $H_2O$: Acid; $OH^-$: Conjugate acid.
Work Step by Step
As we wrote in the question above, the reaction for $HS{O_4}^-$ acting as a base is:
$H{SO_4}^-(aq) + H_2O(l) \lt -- \gt H_2SO_4(aq) + OH^-(aq)$
- Identify the conjugate acid-base pairs of this reaction:
1. Identify the base and the acid in the reactants:
- $HS{O_4}^-$ is turning into $H_2SO_4$; So it is gaining a proton. Therefore:
$H{SO_4}^-$ is a base, and $H_2SO_4$ is its conjugate acid.
- $H_2O$ is turning into $OH^-$; So it is losing a proton. Therefore:
$H_2O$ is an acid, and $OH^-$ is its conjugate base.
