Homework Help

problem 23.144which diagram corresponds to the orbital occupancy of the cobalt ion in...

user profile pic

kathyyyyyy123 | Student, Undergraduate | Honors

Posted July 14, 2013 at 11:18 PM via web

dislike 1 like

problem 23.144which diagram corresponds to the orbital occupancy of the cobalt ion in [Co(CN)6]^3-?

Images:
This image has been Flagged as inappropriate Click to unflag
Image (1 of 1)

1 Answer | Add Yours

user profile pic

llltkl | College Teacher | Valedictorian

Posted July 15, 2013 at 1:48 AM (Answer #1)

dislike 1 like

The oxidation number of Cobalt in the complex ion `[Co(CN)_6]^(3-)` is +3.

Originally, Cobalt has the electronic configuration of [Ar]3d74s2,

It loses three of its outermost electrons to produce `Co^(3+)` , which has the electronic configuration of [Ar]3d6.

The complex ion `[Co(CN)_6]^(3-)` is octahedral. During its formation, owing to the effect of the field created by six negatively charged  incoming ligands from the direction of six corners of a regular octahedron, the d-orbitals of Co3+ ion is supposed to undergo further splitting, giving it a `t_(2g)-e_g` type of splitting. This requies the degeneracy of five d-orbitals wil be lifted and two new sets of degenerate d-orbitals will result; one lower, `t_(2g)` , containing theree orbitals, and the other higher, possessing two orbitals, named `e_g` .

In the given example, though, scanning through the number of electrons in d-orbitals only gives a clue about the correct answer without going into further niceties. Out of the given options, only option A has six electrons in the d-orbital set, therefore, this is the correct answer.

Sources:

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes