Question

The coordination number of $Co$ in $[Co\left(e{n}_{2}C{l}_2\right]Cl$ is:

• A. 6
• B. 4
• C. 0
• D. 3

Answer 1

Answer: (A)

Co-ordination number is defined as the number of co-ordinate bonds (in the co-ordination sphere) of the central metal atom (Co) with the ligands (en and $Cl)$
In the given complex, Co binds with two a bi-dentate ligand en
$(2\times 2=4)$ and two mono-dentate ligand
$Cl(2\times 1=2)$.
Therefore, its co-ordination number is $4+2=6$.