Question

$d$ – orbitals of metal lose their degeneracy in:

• A. Blue vitriol
• B. Anhydrous $CuS{O}_4$
• C. Potassium ferrocyanide
• D. Potassium ferricyanide

Answer 1

Answer: (A), (C), (D)

Potassium ferricyanide

Anhydrous $CuS{O}_4$ is an ionic compound and hence there is no loss of degeneracy in $d$-orbitals.
Blue vitriol, however, is a coordinate complex. It is $\left[CuS{O}_4\right(H_{2}O{)}_4].H_{2}O$. The ligands approach along the axes which leads to a loss of degeneracy in the $d$-orbitals.
Potassium ferrocyanide and potassium ferricyanide, both are octahedral complexes. Here also, ligands approach along the axes owing to which the degeneracy is lost.