MHTCET 25 Apr 2025 Shift 2 Paper

Concept:Ligand field strength is the ability of a ligand to split the d-orbitals of a metal ion, and its relative order is given by the spectrochemical series.Explanation:According to the spectrochemical series, the increasing order of field strength is:$$\mathrm{I}^{-} < \mathrm{Br}^{-} < \mathrm{Cl}^{-} < \mathrm{S}^{2-} < \mathrm{F}^{-} < \mathrm{OH}^{-} < \mathrm{C}_{2}\mathrm{O}_{4}^{2-} < \mathrm{H}_{2}\mathrm{O} < \mathrm{NCS}^{-} < \mathrm{NH}_{3} < \mathrm{en} < \mathrm{CN}^{-} < \mathrm{CO}$$From this series, the relevant part for the given ions is:$$\mathrm{I}^{-} < \mathrm{Cl}^{-} < \mathrm{S}^{2-} < \mathrm{OH}^{-}$$Comparing the options, only option B follows this exact order: $\mathrm{I}^{-} < \mathrm{Cl}^{-} < \mathrm{S}^{2-} < \mathrm{OH}^{-}$.The other options place $\mathrm{Cl}^{-}$ before $\mathrm{I}^{-}$ or reverse the positions of $\mathrm{S}^{2-}$ and $\mathrm{OH}^{-}$, which contradicts the spectrochemical series.Answer:B. $\mathrm{I}^{-} < \mathrm{Cl}^{-} < \mathrm{S}^{2-} < \mathrm{OH}^{-}$