question_answer

In which of the following the magnetic character is not correct?

A) \[CuCl_{4}^{2}-1\]unpaired electron

B)        \[[Fe{{({{H}_{2}}{{O}_{6}}]}^{2+}}-5\]unpaired electrons

C)        \[{{[Zn{{(N{{H}_{3}})}_{2}}]}^{2+}}\]Diamagnetic

D)        \[{{[Co{{F}_{6}}]}^{3-}}-4\]unpaired electrons

Correct Answer: B

Solution :

In \[{{[Fe{{({{H}_{2}}O)}_{6}}]}^{2+}}\] the \[Fe(II)\] ion has \[3{{d}^{6}}\] electronic configuration and pairing of electron in \[3d\] orbital does not take place due to the presence of weak field ligand\[{{H}_{2}}O\]. Hence, there are four unpaired electrons in \[{{[Fe{{({{H}_{2}}O)}_{6}}]}^{2+}}\]ion.