Question

Answer the following question.

How stability of the coordination compounds can be explained in terms of equilibrium constants?

Answer 1

The stability of the complex can be explained in terms of K. Higher the value of K larger is the thermodynamic stability of the complex. The equilibria for the complex formation with the corresponding K values are given below.

\[\ce{Ag+ + 2CN- -> [Ag(CN)2]-}\] K = 5.5 ×10¹⁸

\[\ce{Cu^2+ + 4CN- -> [Cu(CN)4]^2-}\]  K = 2.0 ×10²⁷

\[\ce{Co^3+ + 6NH3 -> [Co(NH3)6]^3+}\]  K = 5.0 ×10³³

Among the above equilibrium constant data, [Co(NH₃)₆] ³⁺ is more stable than [Ag(CN)₂]^– and [Co(NH₃)₆]³⁺ because [Co(NH₃)₆]³⁺ has higher value of equilibrium constant.