What is the correct electronic configuration of the central atom in K4[Fe(CN)6] based on crystal field theory ?

Question : What is the correct electronic configuration of the central atom in K4[Fe(CN)6] based on crystal field theory ?

answer : from all above options the correct answer is option (2)  t62g eg0

answer explanation : In the presence of a strong-field ligand CN etc., the electrons pair up because △0 is large enough to overcome the energy required to pair up the electron in the same orbital, that is pairing energy (P). This results in filling of the lower energy t2g d-orbitals. Thus, the electronic configuration of Fe2+ in complex K4[Fe(CN)6] t62g eg0
that is why we have marked option (2) for correct answer so Answer (2)

in short we can say that –

If we see the central atom of compound K4[Fe(CN)6] then we will find that

Fe contains [Ar] 3d6 4s2 electronic configuration in ground state.

Now if see the electronic configuration of Fe2+ that will be 3d64s0 , that is why we have marked option (2) for correct answer.

for more detail have a look at the figure given below –