9.19 [Cr(NH3)6]3+ is paramagnetic while [Ni(CN)4]2– is diamagnetic. Explain why?
In [Cr(NH3)6]3+, Cr is in the +3 oxidation state i.e., 3 configuration. Also, is a weak field ligand that does not cause the pairing of the electrons in the 3d orbital.
Therefore, it undergoes hybridization and the electrons in the 3d orbitals remain unpaired. Hence, it is paramagnetic in nature.
In [Ni(CN)4]2-, Ni oxidation is +2 and its electronic configuration is 3d8 configuration.
is a strong field ligand. Hence, it paired the 3d electrons. Then, undergoes hybridization.
As there are no unpaired electrons, it is diamagnetic in nature.