The number of unpaired electrons in the complex ion \([CoF_6]^{3–}\) is: (Atomic No.of Co = 27)
- 2
- 3
- 4
- Zero
The Correct Option is C
Solution and Explanation
Cobalt has an atomic number of 27. The electron configuration for a neutral cobalt atom (Co) is: 1s2 2s2 2p6 3s2 3p6 4s2 3d7.
When cobalt forms the complex \([CoF_6]^{3-}\), it loses three electrons to become \(Co^{3+}\): 1s2 2s2 2p6 3s2 3p6 4s0 3d6.
Now, you can count the number of unpaired electrons in the 3d orbitals. In this case, there are 4 unpaired electrons.
So, the correct answer is (C) : 4
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Concepts Used:
Coordination Compounds
A coordination compound holds a central metal atom or ion surrounded by various oppositely charged ions or neutral molecules. These molecules or ions are re-bonded to the metal atom or ion by a coordinate bond.
Coordination entity:
A coordination entity composes of a central metal atom or ion bonded to a fixed number of ions or molecules.
Ligands:
A molecule, ion, or group which is bonded to the metal atom or ion in a complex or coordination compound by a coordinate bond is commonly called a ligand. It may be either neutral, positively, or negatively charged.