Amongst Ni(CO)4, [Ni(CN)4]2− and NiCl2−4:
Amongst Ni(CO)4, [Ni(CN)4]2− and NiCl2−4:
The correct option is C Ni(CO)4 and [Ni(CN)4]2− are diamagnetic; and NiCl2−4 is paramagnetic.
Ni(CO)4=Ni+4CO
The valence shell electronic configuration of ground state Ni atom is 3d84s2.
All of these 10 electrons are pushed into 3d orbitals and get paired up when strong field CO ligands approach Ni atom. The empty 4s and three 4p orbitals undergo sp3 hybridization and form bonds with CO ligands to give Ni(CO)4. Thus, Ni(CO)4 is diamagnetic.
[Ni(CN)4]2−=Ni2++4CN−
In [Ni(CN)4]2−, there is Ni2+ ion for which the electronic configuration in the valence shell is 3d84s0.
In presence of strong field CN− ions, all the electrons are paired up. The empty 4d, 3s and two 4p orbitals undergo dsp2 hybridization to make bonds with CN− ligands in square planar geometry. Thus [Ni(CN)4]2− is diamagnetic.
NiCl2−4=Ni2++4Cl−
Again in NiCl2−4, there is Ni2+ ion, However, in presence of weak field Cl− ligands, NO pairing of d-electrons occurs. Therefore, Ni2+ undergoes sp3 hybridization to make bonds with Cl− ligands in tetrahedral geometry. As there are unpaired electrons in the d-orbitals, NiCl2−4 is paramagnetic.
Ni(CO)4 and [Ni(CN)4]2− are diamagnetic; and NiCl2−4 is paramagnetic.
Ni(CO)4=Ni+4CO
The valence shell electronic configuration of ground state Ni atom is 3d84s2.
All of these 10 electrons are pushed into 3d orbitals and get paired up when strong field CO ligands approach Ni atom. The empty 4s and three 4p orbitals undergo sp3 hybridization and form bonds with CO ligands to give Ni(CO)4. Thus, Ni(CO)4 is diamagnetic.
[Ni(CN)4]2−=Ni2++4CN−
In [Ni(CN)4]2−, there is Ni2+ ion for which the electronic configuration in the valence shell is 3d84s0.
In presence of strong field CN− ions, all the electrons are paired up. The empty 4d, 3s and two 4p orbitals undergo dsp2 hybridization to make bonds with CN− ligands in square planar geometry. Thus [Ni(CN)4]2− is diamagnetic.
NiCl2−4=Ni2++4Cl−
Again in NiCl2−4, there is Ni2+ ion, However, in presence of weak field Cl− ligands, NO pairing of d-electrons occurs. Therefore, Ni2+ undergoes sp3 hybridization to make bonds with Cl− ligands in tetrahedral geometry. As there are unpaired electrons in the d-orbitals, NiCl2−4 is paramagnetic.
