A complex compound of Co³⁺ with molecular formula CoClx. yNH₃ gives a total of 3 ions when dissolved in water. How many Cl^– ions satisfy both primary as well as secondary valencies in this complex?

1

Considering the primary valency of Co³⁺ is 3 and the secondary valency is 6, we need to determine the number of Cl^- ions that satisfy both valencies.

Since the complex dissociates into 3 ions when dissolved in water, we know that one of these ions is Co³⁺. To satisfy the primary valency of 3, we need 3 Cl^- ions.

Out of the remaining two ions, one Cl^- ion satisfies both the primary and secondary valencies. This Cl^- ion is directly bonded to the cobalt ion and also acts as a ligand, contributing to the coordination number of 6.

Therefore, the correct answer is (2), 1 Cl^- ion that satisfies both primary and secondary valencies.