Question

Amongst the following ions which one has the highest magnetic moment value?
(i) $[Cr(H_2O)_6]^{3+}$
(ii) $[Fe(H_2O)_6]^{2+}$
(iii)$[Zn(H_2O)_6]^{2+}$

Answer 1

(i) No. of unpaired electrons in$[Cr(H_2O)_6]^{ 3+}$ = 3
Then, $μ=\sqrt{n(n+2)}$
$=\sqrt{3(3+2)}$
$=\sqrt{15}$
~4BM

(ii) No. of unpaired electrons in$[Fe(H_2O)_6]^{ 2+} = 4$
Then, $μ=\sqrt{n(n+2)}$
$=\sqrt{4(4+2)}$
$=\sqrt{24}$
~5BM

(iii) No. of unpaired electrons in $[Zn(H_2O)_6]^{ 2+} = 0$
Hence, $[Fe(H_2O)_6]^{ 2+}$ has the highest magnetic moment value.