The complex ion [Cr(CN)₆]^4- has magnetic properties that correspond to how many unpaired electrons? A) 0 B) 1 C) 2 D) 3 E) 5

Question

Quizplus · Accepted Answer

The oxidation state of Cr in the complex ion is +2. The electronic configuration of Cr2+ ion is [Ar] 3d4. In [Cr(CN)₆]^4-, CN is a strong field ligand that will cause the d-orbitals to pair up preferentially. The sulfur ligand is a weak field ligand, so the electrons in the d-orbitals will have a higher probability of being unpaired. The complex ion has a low spin configuration because it has a weak field ligand ([S]) followed by a strong field ligand ([CN]). In a low spin configuration, the electrons will fill up the d-orbitals in such a way that unpaired electrons are minimized. Since there are two unpaired electrons in the d-orbitals (one in each box), the answer is (C) 2.

The Complex Ion [Cr(CN)6]4- Has Magnetic Properties That Correspond to How

The Complex Ion [Cr(CN)₆]^4- Has Magnetic Properties That Correspond to How