The IUPAC name for the complex $[\text{Co}({\text{NO}}_2)({\text{NH}}_3{)}_5]{\text{Cl}}_2$ is:

1. Ligands: $5$ ammine (${\text{NH}}_3$) and $1$ nitro (${\text{NO}}_2^{-}$). Alphabetically, ammine comes before nitro.2. Naming ligands: pentaammine nitrito-N (or nitro).3. Central metal: Cobalt.4. Oxidation state: $x+(0\times 5)+(-1)=+2$ (from the two ${\text{Cl}}^{-}$ outside) $⟹x=+3$. So Cobalt (III).5. Anion: chloride.Full name: pentaammine nitrito-N-cobalt (III) chloride.