Which of the following coordination entities is expected to exhibit the maximum magnitude of (octahe — Coordination Compounds Chemistry Question

💡 Solution & Explanation

The magnitude of $\Delta_o$ depends on the central metal, its oxidation state, and the strength of the ligand. In all options, the central metal is $Co^{3+}$. Therefore, $\Delta_o$ depends entirely on the position of the ligand in the spectrochemical series. The order of ligand strength is $H_2O < C_2O_4^{2-} < NH_3 < CN^-$. Since $CN^-$ is the strongest field ligand, it causes the maximum splitting, leading to the largest $\Delta_o$.