The spin only magnetic moment value (in Bohr magneton units) of $\mathrm{Cr}(\mathrm{CO})_{6}$ is

JEE Advanced · 2009 · 12 Apr 2009 · Paper 2 · Coordination Compounds

The spin only magnetic moment value (in Bohr magneton units) of

Cr (CO)_{6}

(A)0✓ Correct
(B)2.84
(C)4.90
(D)5.92

Answer: (A)

Solution

Cr (CO)_{6}

, chromium is in zero oxidation state with electronic configuration

[Ar] 3 d^{5} 4 s^{1}

. Since CO is a strong field ligand, it causes pairing of all electrons. Therefore, there are no unpaired electrons, and the spin-only magnetic moment is zero.

JEE Advanced · 2009 · 12 Apr 2009 · Paper 2 · Single correct option

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