Answer
$OH^-$ and $O^{2-}$ are a conjugate acid-base pair.
Work Step by Step
- Fast method:
A conjugate acid-base pair has exactly one $H^+$ as a difference. So, this is a valid pair.
- Other method:
1. Identify the base:
- $O^{2-}$
** In this case, both substances are bases, but, $O^{2-}$ is stronger, and it has the lower quantity of hydrogens.
2. Add a $H^+$ to it:
- $OH^-$
Compare it with the other substance:
$ OH^- = OH^-$
- So, this is a conjugate acid-base pair.
