Exams › NEET › Chemistry

The number of unpaired electrons in the complex [CoF6]3- is (Atomic no.: Co = 27)

1. Zero
2. 2
3. 3
4. 4

Correct answer: 4

Solution

In [CoF6]3-, cobalt is in the +3 oxidation state (Co3+), with an electronic configuration of 3d6. Fluoride (F-) is a weak field ligand, so it does not cause pairing of electrons. Thus, the 3d6 configuration has 4 unpaired electrons.

Related NEET Chemistry questions

• What is the IUPAC name of \( K_{2}\left[P t C l_{6}\right] ? \)
• The structures of \( \left[N i(C O)_{4}\right] \) and \( \left[N i\left(\left(P h_{3}\right)_{3} P\right)_{2} C l_{2}\right] \) are:
• The IUPAC name of \( \left[\mathrm{Ni}\left(\mathrm{NH}_{3}\right)_{4}\right]\left[\mathrm{NiCl}_{4}\right] \) is :
• Some salts, although containing two different metallic elements, give test for one of them in solution. Such salts are:
• Actinides have higher tendency to form complexes than Lanthanides, due to
• Select the correct order of ions with respect to their ionic radii.

⚔️ Practice NEET Chemistry free + battle 1v1 →