EAMCET Engineering 2005 Solved Paper

As cobalt is present as Co3+ and co-ordination number of cobalt is 6 , the molecular formula of compound should be CoCl3⋅yNH3. Now, as it gives a total of 3 ions when dissolved in water, its structural formula must be [CoCl(NH3)5]Cl2
[CoCl(NH3)5]Cl2⇌[CoCl(NH3)5]2++2Cl−
Thus only one Cl−ion is satisfying both primary and secondary valency of Co3+ in this compound.