Answer:
paramagnetic
Explanation:
The complex ion is : [Cr(CN)₆]³⁻
Oxidation state of Cr in [Cr(CN)₆]³⁻ is:
x + (-1)6 = -3
x = +3
CN⁻ is a strong field ligand which can result in pairing of the electrons.
The electronic configuration of Cr is:
1s²2s²2p⁶3s²3p⁶3d⁵4s¹
The electronic configuration of Cr³⁺ is:
1s²2s²2p⁶3s²3p⁶3d³
These 3 electrons will be singly present in the 3 degenerate t₂g orbitals and per Hund's rule, pairing will not occur in the same level energy orbitals. So , no. of unpaired electrons will be 3 and the complex will be paramagnetic.
