Question

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

CoCl₃·3NH₃

Answer 1

The complex CoCl₃·3NH₃ follows Werner’s theory, where cobalt (Co) has a +3 oxidation state (primary valency) and forms six bonds in total. Three chloride ions (Cl⁻) are attached through primary valency, and three ammonia molecules (NH₃) are attached through secondary valency. The structure is octahedral with cobalt at the center, bonded to three chloride ions and three ammonia molecules. In solution, it ionizes as:

\[\ce{CoCl3(NH3)3 -> [Co(NH3)3]^3+ + 3Cl^-}\]