MHTCET 16 Apr 2026 Shift 2 Paper

Concept:Ionization isomerism arises when ions inside and outside the coordination sphere exchange places, giving different ions in solution.Explanation:Given complex: $\left[\mathrm{Cr}\left(\mathrm{H}_{2}\mathrm{O}\right)_{4}\mathrm{Cl}\left(\mathrm{NO}_{2}\right)\right]\mathrm{Cl}$Here, $\mathrm{NO}_{2}^{-}$ is inside the coordination sphere and $\mathrm{Cl}^{-}$ is outside.For ionization isomerism, exchange these ions:Coordinated $\mathrm{NO}_{2}^{-}$ swaps with the outer sphere $\mathrm{Cl}^{-}$.Thus, the isomer formed is:$\left[\mathrm{Cr}\left(\mathrm{H}_{2}\mathrm{O}\right)_{4}\mathrm{Cl}_{2}\right]\left(\mathrm{NO}_{2}\right)$Option C, $\left[\mathrm{Cr}\left(\mathrm{H}_{2}\mathrm{O}\right)_{4}\mathrm{Cl}(\mathrm{ONO})\right]\mathrm{Cl}$, is a linkage isomer because $\mathrm{NO}_{2}^{-}$ changes bonding atom from N to O.Answer:Option B: $\left[\mathrm{Cr}\left(\mathrm{H}_{2}\mathrm{O}\right)_{4}\mathrm{Cl}_{2}\right]\left(\mathrm{NO}_{2}\right)$