Question

Which of the following statements are true about [CoF₆]³⁻ ion?
I) The complex has octahedral geometry.
II) Coordination number of Co is 3 and oxidation state is +6.
(III) The complex is sp³d² hybridised.
(IV) It is a high spin complex.

• A. I, II and IV
• B. I, III and IV
• C. II and IV
• D. II, III and IV

Hint:

The [CoF₆]³⁻ complex is octahedral, sp³d² hybridised, high spin, with Co in +3 oxidation state and coordination number 6.

Answer 1

The Correct Option is B

The [CoF₆]³⁻ complex has octahedral geometry and is sp³d² hybridised. Since fluoride is a weak field ligand, the complex is high spin. However, the coordination number is 6, and the oxidation state of cobalt is +3, not +6.