# How many isomers are possible for [Cr(NO_2)(NH_3)_5]Cl_2?

For the complex ion ${\left[C r \left(N {O}_{2}\right) {\left(N {H}_{3}\right)}_{5}\right]}^{2 +}$, only the one isomer would be available but for the ambident nature of the ligand, $N {O}_{2}^{-}$.
$\text{Nitro-nitrito}$ isomerism can occur, depending on whether the ligand is $\text{N-bound, nitro}$ or $\text{O-bound, nitrito}$; and thus 2 isomers are possible. The $N {O}_{2}^{-}$ ligand can also bind in a chelate fashion, but I doubt it is doing so in a co-ordinatively saturated $C r \left(I I I +\right)$ complex.