JEE Main 2022 — Coordination Compounds Question with Solution

Crystal field splitting $$\left({\Delta }_0\right)$$ for octahedral complexes depends on oxidation state of the metal as well as to which transition series the metal belongs. For the same oxidation state, the crystal field splitting $$\left({\Delta }_0\right)$$ increases as we move from $$3d\to 4d\to 5d$$

$${\mathrm{Cr}}^{3+}$$ and $${\mathrm{Fe}}^{3+}$$ belong to $$3d$$ series, $${\mathrm{Mo}}^{3+}$$ belongs to $$4d$$ series and $${\mathrm{Os}}^{3+}$$ belongs to $$5d$$ series.

Therefore crystal field splitting $$\left({\Delta }_0\right)$$ is highest for $${\left[\mathrm{Os}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$$.