Question

Calculate the magnetic moment of the following coordination entities.

(i) [Cr(H₂O)₆]⁺³,
(ii) [Fe(H₂O)₆]⁺³,
(iii) [Zn(H₂O)₆]⁺²

Answer 1

The oxidation states are (i) Cr(III); (ii) Fe(II) and (iii) Zn(II)

(i) E.C of Cr⁺³ = 3d³:

no ofunpaired electrons = 3

Magnetic moment = \(\sqrt{3 (3 + 2)}\) = √15

(ii) E.C of Fe⁺² = 3d⁶:

no of unpaired electrons = 4

Magnetic moment = \(\sqrt{4(4 + 2)}\) = √24

(iii) E. C of Zn⁺² = 3d¹⁰:

no of unpaired electrons = 0

Magnetic moment = 0