Question

What can be inferred from the magnetic moment value of the following complex species?

Example	Magnetic Moment (BM)
K4[Mn(CN)6]	2.2

Answer 1

Magnetic Moment (μ) = `sqrt("n"("n" + 2))` BM

When n = 1, μ = `sqrt(1(1 + 2))` = 1.73 BM ≈ 2

When n = 2, μ = `sqrt(2(2 + 2)` = 2.83 BM ≈ 3

When n = 3, μ = `sqrt(3(3 + 2))` = 3.87 BM ≈ 4

When n = 4, μ = `sqrt(4(4 + 2))` = 4.90 BM ≈ 5

When n = 5, μ = `sqrt(5(5 + 2))` = 5.92 BM ≈ 6

K₄[Mn(CN)₆]: The oxidation state of Mn is +2, and Mn²⁺ has an electronic configuration of [Ar]3d⁵.

As μ = 2.2 BM which corresponds to one unpaired electron. The orbital diagram for Mn²⁺ is:

3d
↑↓	↑↓	↑