Which of the following has the highest spin-only magnetic moment value?

1. Ti3+

2. Mn2+

3. Fe2+

4. Co3+

HINTμ = n(n+2) BM

Explanation: Ion contains the maximum number of unpaired electrons has high magnetic moment values

Spin magnetic moment is√n(n+2), where n is the number of unpaired electrons. 

STEP 1: The configuration of ions are as follows:

Ti3+ = Ar3d1
1 unpaired electron

Mn2+ = Ar3d5 
5 unpaired electron 

Fe2+ = Ar3d6 
four unpaired electron

Co3+ = Ar3d6 
Four unpaired electron 


The Mn2+ ion contains a maximum number of unpaired electrons, hence, it has a high spin-only magnetic moment value.