JEE Mains · Chemistry · STD 12 - 4. d and f- block elements
Consider the transition metal ions \(Mn^{3+}\) \(Cr^{3+}\) \(Fe^{3+}\) and \(Co^{3+}\) and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is
- A \(Cr^{3+}>Fe^{3+}>Co^{3+}>Mn^{3+}\)
- B \(Mn^{3+}>Fe^{3+}>Co^{3+}>Cr^{3+}\)
- C \(Fe^{3+}>Co^{3+}>Mn^{3+}>Cr^{3+}\)
- D \(Cr^{3+}>Mn^{3+}>Fe^{3+}>Co^{3+}\)
Answer & Solution
Correct Answer
(D) \(Cr^{3+}>Mn^{3+}>Fe^{3+}>Co^{3+}\)
Step-by-step Solution
Detailed explanation
\(Co^{3+}\rightarrow3d^{6}\Rightarrow t_{2g}^{2,2,2}e_{g}^{0,0}\), unpaired electron \(=0\) \(Fe^{3+}\rightarrow3d^{5}\Rightarrow t_{2g}^{2,2,1}e_{g}^{0,0}\) unpaired electron \(=1\) \(Cr^{3+}\rightarrow3d^{3}\Rightarrow t_{2g}^{1,1,1}e_{g}^{0,0}\) unpaired electron \(=3\)…
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