Question

The spin-only magnetic moment of Hexacyanomanganate(II) ion is.........BM

• A. 1.73 BM
• B. 5.90 BM
• C. 4.90 BM
• D. 3.87 BM

Answer 1

The Correct Option is A

Option 2: 1.73 BM

To determine the spin-only magnetic moment of the Hexacyanomanganate(II) ion, [Mn(CN)₆]^4-, we need to find the number of unpaired electrons in the Mn²⁺ ion.

1. Electronic configuration of Mn:

Mn (Z = 25): [Ar] 3d⁵ 4s²

2. Electronic configuration of Mn²⁺:

Mn²⁺: [Ar] 3d⁵

3. Effect of CN^- ligand:

CN^- is a strong field ligand. In the presence of strong field ligands, the d-electrons pair up. However, since there are 5 d-electrons, there will be one unpaired electron in the t_2g orbital. The configuration will be t_2g⁵eg⁰

4. Number of unpaired electrons (n):

n = 1

5. Spin-only magnetic moment formula:

μ_s = √[n(n+2)] BM

6. Calculation:

μ_s = √[1(1+2)] BM

μ_s = √[1(3)] BM

μ_s = √3 BM

μ_s ≈ 1.73 BM

Therefore, the spin-only magnetic moment of [Mn(CN)₆]^4- is approximately 1.73 BM.

The correct answer is:

Option 2: 1.73 BM