Which is diamagnetic?

  • Option 1)

    \left [ Fe(CN)_{6} \right ]^{3-}

  • Option 2)

    \left [ Co(F_{6}) \right ]^{3-}

  • Option 3)

    \left [ Ni(CN)_{4} \right ]^{2-}

  • Option 4)

    \left [ Ni(Cl)_{4} \right ]^{-2}

 

Answers (1)
V Vakul

As we learnt in

Magnetic Moments (spin only) -

\sqrt{n\left ( n+2 \right )} where n= number of unpaired electron.

- wherein

Number of unpaired e^{-} s and corresponding magnetic moments

\\1\rightarrow 1.7\\2\rightarrow 2.8\\3\rightarrow 3.9\\4\rightarrow 4.9\\5\rightarrow 5.9

 

Electronic configuration of Ni2+ : 3d8 4s0 4p0

Since CN- is a strong field ligand, so electron in 3d orbitals will pair up.

Electronic configuration of Ni2+ in [Ni(CN)4]2- :

Since there are no unpaired electrons, so the complex is diamagnetic in nature. 

 


Option 1)

\left [ Fe(CN)_{6} \right ]^{3-}

Incorrect

Option 2)

\left [ Co(F_{6}) \right ]^{3-}

Incorrect

Option 3)

\left [ Ni(CN)_{4} \right ]^{2-}

Correct

Option 4)

\left [ Ni(Cl)_{4} \right ]^{-2}

Incorrect

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