What is meant by stability of a coordination compound in solution? State the factors which govern stability of complexes.

(N/A) The stability of a complex in a solution refers to the degree of association between the two species involved in a state of equilibrium. Stability can be expressed quantitatively in terms of stability constant or formation constant.
$M + nL \longleftrightarrow ML_n$
Stability constant,$\beta = \frac{[ML_n]}{[M][L]^n}$
For this reaction,the greater the value of the stability constant,the greater is the proportion of $ML_n$ in the solution.
Stability can be of two types:
$(a)$ Thermodynamic stability: The extent to which the complex will be formed or will be transformed into another species at the point of equilibrium is determined by thermodynamic stability.
$(b)$ Kinetic stability: This helps in determining the speed with which 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: The greater the charge on the central metal ion,the greater is the stability of the complex.
$(b)$ Basic nature of the ligand: $A$ more basic ligand will form a more stable complex.
$(c)$ Presence of chelate rings: Chelation increases the stability of complexes.