Question

‘Spin only’ magnetic moment is the same for which of the following ions?

1. Ti³⁺
2. Cr²⁺
3. Mn²⁺
4. Fe²⁺
5. Sc³⁺

Choose the most appropriate answer from the options given below:

Options

• B and C only

• A and D only

• B and D only

• A and E only

Answer 1

B and D only

Explanation:

The species which have the same number of unpaired electrons have the same spin only magnetic moment.

Electronic configuration of:

Ti³⁺ = [Ar] 3d¹

Number of unpaired electrons = 1

Cr²⁺ = [Ar] 3d⁴

Number of unpaired electrons = 4

Mn²⁺ = [Ar] 3d⁵

Number of unpaired electrons = 5

Fe²⁺ = [Ar] 3d⁶

Number of unpaired electrons = 4

Sc³⁺ = [Ar]

Number of unpaired electrons = 0

Hence Cr²⁺ and Fe²⁺ have the same spin only magnetic moment.