The correct order of magnetic moments (spin only values in B.M.) among the following is: (Atomic numbers: Mn = 25; Fe = 26, Co = 27 ) - Chemistry MCQ AIEEE 2004 2026 | ExamTest.live

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The correct order of magnetic moments (spin only values in B.M.) among the following is: (Atomic numbers: Mn = 25; Fe = 26, Co = 27)

Solution & Step-by-step Explanation

Spin-only magnetic moment μ = n (n + 2) B.M. where n is the number of unpaired electrons. [MnCl_{4}]^{2 -} : Mn^{2 +} is d^{5} . Cl^{-} is a weak field ligand, so n = 5 . μ \approx 5.9 B.M. . [CoCl_{4}]^{2 -} : Co^{2 +} is d^{7} . Cl^{-} is weak field, arrangement is e^{4} t_{2}^{3} for tetrahedral, so n = 3 . μ \approx 3.9 B.M. . [Fe (CN)_{6}]^{4 -} : Fe^{2 +} is d^{6} . CN^{-} is a strong field ligand, so all electrons pair up (t_{2 g}^{6}). n = 0 . μ = 0 . Order: [MnCl_{4}]^{2 -} > [CoCl_{4}]^{2 -} > [Fe (CN)_{6}]^{4 -} .

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The correct order of magnetic moments (spin only values in B.M.) among the following is: (Atomic numbers: Mn = 25; Fe = 26, Co = 27)

[MnCl_{4}]^{2 -} > [CoCl_{4}]^{2 -} > [Fe (CN)_{6}]^{4 -}

[Fe (CN)_{6}]^{4 -} > [CoCl_{4}]^{2 -} > [MnCl_{4}]^{2 -}

[Fe (CN)_{6}]^{4 -} > [MnCl_{4}]^{2 -} > [CoCl_{4}]^{2 -}

[\text{CoCl}_4]^{2-}$

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