Question -
Answer -
The stability of a complex in a solutionrefers to the degree of association between the two species involved in a stateof equilibrium. Stability can be expressed quantitatively in terms of stabilityconstant or formation constant.
Forthis reaction, the greater the value of the stability constant, the greater isthe proportion of ML3 in the solution.
Stability can be of two types:
(a) Thermodynamicstability:
The extent to which the complex will beformed or will be transformed into another species at the point of equilibriumis determined by thermodynamic stability.
(b) Kineticstability:
This helps in determining the speed withwhich the transformation will occur to attain the state of equilibrium.
Factors that affect the stability of a complex are:
(a) Charge on the central metal ion: Thegreaterthe charge on the central metal ion, the greater is the stability of thecomplex.
2. Basic nature ofthe ligand: A morebasic ligand will form a more stable complex.
2. Presence ofchelate rings: Chelationincreases the stability of complexes.