Answer
$N{O_2}^-$ is the stronger base.
Work Step by Step
- $NO_3^-$ is the conjugate base of a strong acid ($HNO_3$), therefore, it has negligible basicity.
- $NO_2^-$ is the conjugate base of a weak acid ($HNO_2$), therefore, it is a weak base.
Stronger acids have weaker conjugate bases, so, we can compare the strength of the conjugate acids of these bases:
$HNO_3$ and $HNO_2$:
$HNO_3$ is a strong acid, and $HNO_2$ is a weak acid, therefore $HNO_3$ is stronger, and $N{O_3}$^- is the weaker base.
