Question

The spin-only magnetic moment of [Fe(acac)₃] is____μ𝐵 .
(round off to two decimal places)

Answer 1

Correct Answer: 5.91 - 5.92

To determine the spin-only magnetic moment of [Fe(acac)₃], we need to analyze the electronic configuration of the Fe³⁺ ion. In [Fe(acac)₃], the iron is in a +3 oxidation state. The electronic configuration of Fe is [Ar] 3d⁶ 4s². For Fe³⁺, we remove three electrons: two from the 4s orbital and one from the 3d orbital, resulting in an electronic configuration of [Ar] 3d⁵.

For a 3d⁵ configuration, all five d electrons are unpaired. The spin-only magnetic moment (μ_spin-only) is calculated using the formula:

μ = √(n(n+2)) μ_B 

where n is the number of unpaired electrons. Here, n = 5.

Substituting n = 5 into the formula gives:

μ = √(5(5+2)) μ_B = √35 μ_B

Calculating further:

μ = √35 ≈ 5.92 μ_B

This value falls within the specified range of 5.91 to 5.92 μ_B, confirming its accuracy.

Thus, the spin-only magnetic moment of [Fe(acac)₃] is 5.92 μ_B.