The magnetic moment of $[FeF_6]^{4-}$ ion : (a) 4.90 BM (b) 5.92 BM (c) 2.83 BM (d) 1.73 BM

The magnetic moment of [FeF₆]⁴⁻ ion : (a) 4.90 BM (b) 5.92 BM (c) 2.83 BM (d) 1.73 BM

Question 53 of 67

[FeF_6]^{4-}

(a) 4.90 BM

(b) 5.92 BM

(d) 1.73 BM

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$[FeF_6]^{4-}$ contains high-spin $Fe^{2+}$ ( $d^6$ ) with 4 unpaired electrons, giving a spin-only magnetic moment of $\sqrt{24}\approx4.90$ BM.

Since the six $F^-$ ligands each carry charge $-1$ and the overall complex ion charge is $-4$ , the iron must be $Fe^{2+}$ : $x + 6(-1) = -4 \Rightarrow x=+2$ . $Fe^{2+}$ has the configuration $[Ar]3d^6$ . $F^-$ is a weak-field ligand (low in the spectrochemical series), so it does not force electron pairing, and the complex adopts the high-spin octahedral configuration $t_{2g}^4 e_g^2$ , which has 4 unpaired electrons. Using …

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Q.The magnetic moment of $[FeF_6]^{4-}$ ion :

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Q.The magnetic moment of [FeF6]4−[FeF_6]^{4-}[FeF6​]4− ion :

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Q.The magnetic moment of $[FeF_6]^{4-}$ ion :

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