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))`

= `sqrt 3`

= 1.73 BM

≈ 2

When n = 2,

μ = `sqrt(2(2 + 2)`

= `sqrt 8`

= 2.83 BM

≈ 3

When n = 3,

μ = `sqrt(3(3 + 2))`

= `sqrt 15`

= 3.87 BM

≈ 4

When n = 4,

μ = `sqrt(4(4 + 2))`

= `sqrt 24`

= 4.90 BM

≈ 5

When n = 5,

μ = `sqrt(5(5 + 2))`

= `sqrt 35`

= 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
↑↓	↑↓	↑