Question

The total number of unpaired electrons present in the complex K₃[Cr(oxalate)₃] is _________.

Hint:

For $d^1, d^2,$ and $d^3$ configurations in octahedral complexes, the number of unpaired electrons is always equal to the number of d-electrons.

Answer 1

Correct Answer: 3

Step 1: Oxidation state of $Cr$ in $K_3[Cr(ox)_3]$ is $+3$.
Step 2: Electronic configuration of $Cr^{3+} = [Ar] 3d^3$.
Step 3: In an octahedral field, the $d^3$ configuration fills the $t_{2g}$ orbitals: $t_{2g}^3 e_g^0$.
Step 4: All 3 electrons remain unpaired regardless of ligand strength.