28.5.3—Kstab expressions to perform calculations

A Kstab calculation links equilibrium concentrations through the formation expression. Rearrange the expression only after identifying the stoichiometry of the complex.

Substitute concentrations with consistent units, keep powers attached to the correct ligand, and check that the calculated value is chemically plausible relative to the starting amounts.

If Kstab = [[ML]⁺]/([M²⁺][L⁻]), then [[ML]⁺] = Kstab[M²⁺][L⁻]. For ML₂, the ligand concentration is squared instead.

A large Kstab does not mean every metal is complexed regardless of concentration; dilution and competing ligands still change the equilibrium composition.