Chemistry: A Molecular Approach (3rd Edition)

Name of $HNO_{2}(aq)$ is $nitrous\hspace{1mm} acid.$
$HNO_{2}(aq)$ is an oxyacid. Its oxyanion is $NO_{2}^{-}$, i.e nitrite. According to Fig. 3.10, oxyacids with oxanions ending in -ite are named as : $'base name \hspace{1mm}of \hspace{1mm}oxyanion' + ous + acid$ Here, basename is $-nitr$. Hence, name of $HNO_{2}(aq)$ is $nitrous\hspace{1mm} acid.$