Question

Please explain with written answer. No need for diagrams.

Ni(II) adopts tetrahedral geometry when coordinated with Cl-, octahedral geometry with H₂O as the ligand, and square planar geometry with CN-. Explain.

Answer 1

The reason for Ni(II) adopts the tetrahedral geometry for Cl- and square planar with CN- because the CN- is a strong field ligand whereas Cl- is a weak field ligand

The presence of strong field ligand makes all the electron paired leaving 4d,3s and 4p(two orbitals vaccant ) leading to the formation of dsp2 hybridized or square planar geometry

The presence of weak filed ligand makes the electron unpaied in the Ni complex at 4s and 3p forming sp3 hybridization