Arrange the following metal complex/compounds in the increasing order of spin only magnetic moment. Presume all the three, high spin system.
(Atomic numbers Ce = 58, Gd = 64 and Eu = 63)
(a) (NH4)2[Ce(NO3)6]
(b) Gd(NO3)3 and
(c) Eu(NO3)3
Solution
<p>(A) ${}_{58}Ce \to [Xe]4{f^2}5{d^0}6{s^2}$</p>
<p>In complex $C{e^{ + 4}} \to [Xe]4{f^0}5{d^0}6{s^0}$</p>
<p>There is no unpaired electron, so, $\mu$<sub>m</sub> = 0 BM</p>
<p>(B) ${}_{64}Gd \to [Xe]4{f^7}5{d^1}6{s^2}$</p>
<p>In complex, ${}_{64}G{d^{2 + }} \to [Xe]4{f^7}5{d^1}$</p>
<p>There are 8 unpaired electrons.</p>
<p>$\therefore$ ${\mu _m} = \sqrt {8(8 + 2)} = \sqrt {80} = 8.94BM$</p>
<p>(C) ${}_{63}Eu \to [Xe]4{f^9}5{d^0}6{s^0}$</p>
<p>In complex ${}_{63}E{u^{ + 3}} \to [Xe]4{f^6}5{d^0}6{s^0}$</p>
<p>contain six unpaired electrons.</p>
<p>So, ${\mu _m} = \sqrt {6(6 + 2)} = \sqrt {48} BM = 6.93BM$</p>
<p>Hence, order of spin only magnetic moment</p>
<p>$B > C > A$.</p>
About this question
Subject: Chemistry · Chapter: d and f Block Elements · Topic: Properties of Transition Metals
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