Looking for classes? Ksquare Career Institute, Bengaluru →
'Spin only' magnetic moment is same for which of the following ions?
A. $Ti^{3+}$ B. $Cr^{2+}$
C. $Mn^{2+}$ D. $Fe^{2+}$
E. $Sc^{3+}$
Choose the most appropriate answer from the options given below:
A
B and C only
B
A and D only
C
B and D only
D
A and E only
Detailed Solution
Species with the same number of unpaired electrons have the same spin-only magnetic moment, $\mu = \sqrt{n(n+2)}$ BM.
$Ti^{3+} = [Ar]\,3d^1$: 1 unpaired electron
$Cr^{2+} = [Ar]\,3d^4$: 4 unpaired electrons
$Mn^{2+} = [Ar]\,3d^5$: 5 unpaired electrons
$Fe^{2+} = [Ar]\,3d^6$: 4 unpaired electrons
$Sc^{3+} = [Ar]$: 0 unpaired electrons
So $Cr^{2+}$ and $Fe^{2+}$ (B and D) have the same spin-only magnetic moment.