The octahedral complex ion [FeCl6]3-

Question

The octahedral complex ion [FeCl6]3-  (A) 5 unpaired electrons (t2g3eg2)  (B) 1 unpaired electron (t2g1)  (C) 3 unpaired electrons (t2g1eg2)  (D) All the electrons are paired

Tardigrade Admin · Accepted Answer

In [FeCl6]3-,Fe is in + 3 oxidation state. Cl is a weak field ligand so the electrons remain unpaired. 26Fe=[Ar]3d64s2;Fe3+=[Ar]3d5 ( 5e-, unpaired electrons) Therefore, option (a)t2g3eg2 is correct.

Q. The octahedral complex ion $[F e C l_{6}]^{3 -}$

5 unpaired electrons $(t_{2 g}^{3} e_{g}^{2})$

1 unpaired electron $(t_{2 g}^{1})$

3 unpaired electrons $(t_{2 g}^{1} e_{g}^{2})$

All the electrons are paired

In $[F e C l_{6}]^{3 -}, F e$ is in + 3 oxidation state. Cl is a weak field ligand so the electrons remain unpaired. $_{26} F e = [A r] 3 d^{6} 4 s^{2}; F e^{3 +} = [A r] 3 d^{5}$ ( $5 e^{-},$ unpaired electrons) Therefore, option $(a) t_{2 g}^{3} e_{g}^{2}$ is correct.

Q. The octahedral complex ion [FeCl6​]3−

5 unpaired electrons (t2g3​eg2​)

1 unpaired electron (t2g1​)

3 unpaired electrons (t2g1​eg2​)