A complex compound of Co ³⁺ with molecular formula CoCl _ x yNH ₃ gives a total of 3 ions when dissolved in water. How many Cl ⁻ ions satisfy both primary and secondary valencies in this complex?

Step-by-step solution

As cobalt is present as Co ³⁺ and co-ordination number of cobalt is 6 , the molecular formula of compound should be CoCl ₃ yNH ₃ . Now, as it gives a total of 3 ions when dissolved in water, its structural formula must be [ CoCl ( NH ₃ )₅ ] Cl ₂ [ CoCl ( NH ₃ )₅ ] Cl ₂ [ CoCl ( NH ₃ )₅ ]²⁺+2 Cl ⁻ Thus only one Cl ⁻ ion is satisfying both primary and secondary valency of Co ³⁺ in this compound.