The spin only magnetic moment value (in Bohr magneton units) of Cr(CO)...
Chromium in Cr (CO)6 is in zero oxidation state and has [Ar]18 3d54s1 as the electronic configuration. However, CO is a strong ligand, hence pairing up of electrons takes place leading to following configuration in Cr(CO)6.
Since the complex has no unpaired electron, its magnetic moment is zero.
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The spin only magnetic moment value (in Bohr magneton units) of Cr(CO)...
Understanding the Magnetic Moment in Cr(CO)6
The magnetic moment of a complex is determined by the presence of unpaired electrons. In the case of Cr(CO)6, we need to analyze its electronic configuration and the effect of the ligands.
Electronic Configuration of Chromium
- Chromium (Cr) has an atomic number of 24.
- Its ground state electronic configuration is [Ar] 3d5 4s1.
- In Cr(CO)6, chromium is in a +3 oxidation state, which results in an electronic configuration of 3d4 (after losing 3 electrons).
CO as a Ligand
- Carbon monoxide (CO) is a strong-field ligand and causes pairing of electrons.
- In an octahedral field created by six CO ligands, the 3d orbitals split into two groups: lower-energy t2g and higher-energy eg orbitals.
Electron Configuration in Cr(CO)6
- The 3d4 configuration under the influence of CO will lead to all four electrons being paired in the t2g orbitals.
- Thus, there are no unpaired electrons in Cr(CO)6.
Calculating the Magnetic Moment
- The spin-only magnetic moment formula is given by the equation: μ = √(n(n+2)), where n is the number of unpaired electrons.
- Since Cr(CO)6 has 0 unpaired electrons (n=0), substituting into the formula gives: μ = √(0(0+2)) = 0.
Conclusion
- Therefore, the spin-only magnetic moment of Cr(CO)6 is 0 Bohr magnetons, confirming that the correct answer is option 'A'.