Question

The complex ion [CoBr6]3− is a high-spin complex and absorbs light at a wavelength greater than 7.70×102 nm . How many unpaired electrons will be present in the complex?

Answer 1

Answer:

4 electrons

Step-by-step explanation:

[CoBr₆]³⁻ contains Cobalt as the central metal ion and 6 bromide atoms are bonded to the metal as ligands.

Bromide is a weak field ligand and thus pairing of the electrons will not take place and the complex, [CoBr₆]³⁻ is a high spin complex.

The oxidation number of Co in [CoBr₆]³⁻ is +3.

The Electronic configuration of Co³⁺ in [CoBr₆]³⁻ (d⁶) in a weak field octahedral environment is $t_{2g}^4 e_g^2$

Number of unpaired electrons = 4 electrons