AP EAPCET 06-Jul-2022 Shift 2 Paper

I. [Fe(CN)6]4−
Atomic number of Fe=26
Ground state configuration of Fe=[Ar]3d64s2
Fe2+=[Ar]3d6
Since, cyanide is a powerful ligand, therefore, all the electrons will be paired.
Number of unpaired electrons in [Fe(CN)6]4−=0
II. [Fe(H2O)6]2+
Atomic number of Fe=26
Ground state configuration of Fe=[Ar]3d64s2
Fe2+=[Ar]3d6
Number of unpaired electrons in [Fe(H2O)6]2+=4.
III. [Co(H2O)6]2+
Atomic number of Co=27
Ground state configuration of Fe=[Ar]3d74s2
Co2+=[Ar]3d7
Number of unpaired electrons in [Co(H2O)6]2+=3
So, the correct order is II > III > I.