Question

The geometry and magnetic behaviour of the complex [Ni(CO)₄] are 

(1) square planar geometry and diamagnetic 

(2) tetrahedral geometry and diamagnetic 

(3) square planar geometry and paramagnetic 

(4) tetrahedral geometry and paramagnetic

Answer 1

(2) tetrahedral geometry and diamagnetic

Answer 2

Geometry: Tetrahedral geometry

Magnetic behaviour: Diamagnetic

Ni(28)= [Ar]3d⁸4s^​​²

^{Unpaired electrons= 0}

^{Therefore, complex is diamagnetic}

Since CO is a strong field ligand, for 4CO ligands hybridisation would be sp^​3 and thus geometry will be tetrahedral.

Answer 3

tedrahedral and diamagnetic