Question

What will be the spin only magnetic moment of high spin and low spin $ d^5 $ electronic system in an octahedral complex?

• A. $ \mu_{\text{high spin}} = 1.73 MB $ and $ \mu_{\text{low spin}} = 5.92 BM $
• B. $ \mu_{\text{high spin}} = 5.92\, BM $ and $ \mu_{\text{low spin}} = 1.73\, BM $
• C. $ \mu_{\text{high spin}} = 4.9\, BM $ and $ \mu_{\text{low spin}} = 2.83\, BM $
• D. $ \mu_{\text{high spin}} = 1.73\, BM $ and $ \mu_{\text{low spin}} = 1.73\, BM $

Answer 1

Answer: (B)

High spin $d^{5}$ system : $t^{3} _{2g}e_{g}^{2}$
$t_{2g}^{3} e_{g}^{2} $
No. of unpaired electrons $(n) = 5$
Magnetic moment, $\mu=\sqrt{n\left(n+2\right)}$ B.M.
$\mu_{\text{high spin}}=\sqrt{5\left(5+2\right)}$
$=5.92$ B.M.
Low spin $d^{5}$ system : $t_{2g}^{5}$
$t^{5}_{2g}$ : ; $n=1$
$\mu_{\text{low spin}} =\sqrt{1\left(1+2\right)}$
$=1.73\,B.M.$