Question

Write the structure of the following complex on the basis of Werner’s theory:

CoCl₃·6NH₃

Answer 1

In the complex CoCl₃·6NH₃, cobalt is in the +3 oxidation state, so its primary valency is 3. The three Cl⁻ ions are linked through primary valency. The coordination number of cobalt is 6, so it forms six secondary valencies with six NH₃ molecules. This gives the octahedral structure, with three chloride ions and six ammonia molecules around the central cobalt ion.