Answer
$N{H_2}^-$ and $NH_3$ 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:
- $N{H_2}^-$
** $NH_3$ can act as a base, too, but ${NH_2}^-$ is stronger, and it has a lower quantity of Hydrogens.
2. Add a $H^+$ to it:
- $NH_3$
Compare it to the other substance:
$N{H_3} = NH_3$
- So, this is a conjugate acid-base pair.
