A coordination compound is made of Co ³⁺ , NH ₃ , and Cl ⁻, 0.1 M solution of this complex when treated with excess silver nitrate gave no precipitate. The formula of the complex and secondary valency of metal are respectively.

Step-by-step solution

Since, no precipitate of AgCl is obtained on treating the compound with silver nitrate that means no Cl ⁻ ions are available outside the coordination sphere. So, correct formula of coordination compound is [ Co ( NH ₃ )₃ Cl ₃ . . Since, central metal Co forms six coordination bonds thus the secondary valency is 6 .