Question

What should be possible $d$-orbital energy levels of $Ni$ in $[Ni(CN{)}_4{]}^{2-}$ ?

• A. $d_{z^2}<d_{xy}<d_{xy}=d_{yz}<d_{x^2-y^2}$
• B. $d_{x^2-y^2}<d_{xy}<d_{z^2}<d_{xy}=d_{yz}$
• C. $d_{xy}=d_{yz}<d_{z^2}<d_{xy}<d_{x^2-y^2}$
• D. $d_{z^2}<d_{xy}=d_{yz}<d_{xy}<d_{x^2-y^2}$

Answer 1

Answer: (C)

$[Ni(CN{)}_4{]}^{2-}$ has square planar geometry with $ds{p}^2$ hybridisation
The order of energies of $d$-orbitals in square planar geometry is:
$d_{xy}=d_{yz}<d_{z^2}<d_{xy}<d_{x^2-y^2}$