How many d electrons are in the cobalt ion of K₃[Co(CN)₆]? A)3 B)5 C)6 D)7 E)4

Question

Quizplus · Accepted Answer

To determine the number of d electrons in a cobalt ion, we need to first determine its oxidation state. In this case, the cobalt ion is part of the complex ion [Co(CN)6]3-, which has a charge of -3. The charge on each cyanide ion is -1, so there must be 6 cyanide ions to give a total charge of -6. Therefore, the cobalt ion must have a charge of +3 to balance the overall charge of the complex ion. 
A cobalt ion with a +3 charge would have lost three electrons from its neutral state, leaving behind 7 electrons in its d subshell. However, the six cyanide ions in the complex are strong field ligands, which cause the d electrons to pair up in the lower energy level. This results in a d6 configuration for the cobalt ion in this complex. Therefore, the answer is (C) 6 d electrons.

How Many D Electrons Are in the Cobalt Ion of K3[Co(CN)6]

How Many D Electrons Are in the Cobalt Ion of K₃[Co(CN)₆]