Chemistry - Coordination Chemistry Question with Solution | TestHub

For $[Cr(N{H}_3{)}_4(N{O}_2{)}_2]Br$, ionisation isomerism is possible because $B{r}^{-}$ (counter ion) can exchange with the coordinated $N{O}_2^{-}$ ion. Linkage isomerism occurs due to the ambidentate nature of $N{O}_2^{-}$, which can coordinate through N (nitro) or O (nitrito). Geometrical isomerism is possible because the octahedral complex has two $N{O}_2^{-}$ ligands that can occupy cis or trans positions. Coordination isomerism is not possible as there is only one complex ion.

Therefore, the correct answer is A, B and C.