question_answer

The correct order of magnetic moments (spin only values in BM) among the following is (Atomic numbers:\[Mn=25,\text{ }Fe=26,\text{ }Co=27\])

A)  \[{{[MnC{{l}_{4}}]}^{2-}}>{{[CoC{{l}_{4}}]}^{2-}}>{{[Fe{{(CN)}_{6}}]}^{4-}}\]

B)  \[{{[MnC{{l}_{4}}]}^{2-}}>{{[Fe{{(CN)}_{6}}]}^{4-}}>{{[CoC{{l}_{4}}]}^{2-}}\]

C)  \[{{[Fe{{(CN)}_{6}}]}^{4-}}>{{[MnC{{l}_{4}}]}^{2-}}>{{[CoC{{l}_{4}}]}^{2-}}\]

D)  \[{{[Fe{{(CN)}_{6}}]}^{4-}}>{{[CoC{{l}_{4}}]}^{2-}}>{{[MnC{{l}_{4}}]}^{2-}}\]

Correct Answer: A

Solution :

 As the number of unpaired electrons in the central atom increases, magnetic moment of the complex increases. In\[{{[MnC{{l}_{4}}]}^{2-}}=[Ar]\] In \[{{[CoC{{l}_{4}}]}^{2-}}=[Ar]\] In \[{{[Fe{{(CN)}_{6}}]}^{4-}}=[Ar]\] \[\therefore \]The order of magnetic moments is \[{{[MnC{{l}_{4}}]}^{2-}}>{{[CoC{{l}_{4}}]}^{2-}}>{{[Fe{{(CN)}_{6}}]}^{4-}}\]