Question

If an ion of Mn has magnetic moment of 3.873 B.M. Then Mn is in which state.

• A. 2
• B. 3
• C. 4
• D. 5

Answer 1

The correct option is C 4

Magnetic moment is given by
$\mu =\sqrt{n(n+2)}=3.873B.M.$
number of unpaired electron n = 3
the electronic configuration of Mn is
$Mn-\left[Ar\right]3d^{5}4s^2$

Remove 3 electron
therefore, Mn should be in +4 oxidation state.