question_answer

The value of the 'spin only' magnetic moment for one of the following configurations is 2.84 BM. The correct one is     AIEEE  Solved  Paper-2005

A) \[{{d}^{5}}\](in strong ligand field)

B) \[{{d}^{3}}\](in weak as well as in strong fields)

C) \[{{d}^{4}}\](in weak ligand field)

D) \[{{d}^{4}}\](in strong ligand field)

Correct Answer: D

Solution :

Magnetic moments depends on the number of unpaired electrons. Pairing of electrons in complex depends on the ligand filled strength. Therefore, calculate the magnetic moment for different configuration given in question. \[{{d}^{5}}\]in strong field \[n=\]unpaired electron\[=1\] Magnetic moment\[=\sqrt{n(n+2)}BM\] \[=\sqrt{3}BM=1.73\,BM\] \[{{d}^{3}}\]in strong/weak field \[n=3\] Magnetic moment \[=\sqrt{15}=3.87\,BM\] \[{{d}^{4}}\]in weak field \[n=4\] Magnetic moment \[=\sqrt{24}=4.90\,BM\] \[{{d}^{4}}\]in strong field \[n=2\] Magnetic moment\[=\sqrt{8}=2.83\text{ }BM\]