The compounds $\left[\mathrm{Cr}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right] {\mathrm{Cl}}_3, \left[\mathrm{Cr}{\left({\mathrm{H}}_2\mathrm{O}\right)}_5\mathrm{Cl}\right] {\mathrm{Cl}}_2. {\mathrm{H}}_2\mathrm{O}$ and $[\mathrm{Cr} {\mathrm{H}}_2\mathrm{O}{)}_4{\mathrm{Cl}}_2]\mathrm{Cl}.2{\mathrm{H}}_2\mathrm{O}$ exhibits :

these isomers will differ in no of water molecules both in coordination sphere and ionization sphere