question_answer

Which of the following complex ions has electrons that are symmetrically filled in both \[{{t}_{2g}}\]and \[{{e}_{g}}\] orbitals? [JEE Main Online Paper (Held On 11 April 2015)]  

A) \[{{[Co{{F}_{6}}]}^{3-}}\]

B) \[{{[Co{{(N{{H}_{3}})}_{6}}]}^{2+}}\]

C) \[{{[Mn{{(CN)}_{6}}]}^{4-}}\]

D) \[{{[Fe{{F}_{6}}]}^{3-}}\]

Correct Answer: D

Solution :

  \[{{\left[ Fe{{F}_{6}} \right]}^{3-}}\]oxidiation state of \[Fe=+3\] \[F{{e}^{+3}}=\left[ Ar \right]3{{d}^{5}},{{F}^{-}}\] is weak field Ligand