The common ion effect is responsible for the reduction in the solubility of an ionic precipitate when a soluble compound combining one of the ions of the precipitate is added to the solution in equilibrium with the precipitate. It states that if the concentration of any one of the ions is increased, then, according to Le Chatelier\'s principle, the ions in excess should combine with the oppositely charged ions. Some of the salt will be precipitated until the ionic product is equal to the solubility of the product. In simple words, common ion effect is defined as the suppression of the degree of dissociation of a weak electrolyte containing a common ion. Many transition metal compounds violate this rule due to the formation of complex ions. For example, copper(I) chloride is insoluble in water, but it dissolves when chloride ions are added, such as when hydrochloric acid is added. This is due to the formation of soluble CuCl2 complex ions.By pulling Ag+ ions out of this equilibrium, the equilibrium must shift to replace them as best it can. i.e. more AgBr(s) must go into solution. The solubility of a slightly soluble salt increases when one of its ions can be changed to a soluble complex ion.Adding the ammonia introduces another equilibrium and we can sum the two equilibrium present.Original EquilibriumAgBr(s) <=====> Ag+(aq) + Br-(aq) Ksp = [Ag+][Br-] Solution The common ion effect is responsible for the reduction in the solubility of an ionic precipitate when a soluble compound combining one of the ions of the precipitate is added to the solution in equilibrium with the precipitate. It states that if the concentration of any one of the ions is increased, then, according to Le Chatelier\'s principle, the ions in excess should combine with the oppositely charged ions. Some of the salt will be precipitated until the ionic product is equal to the solubility of the product. In simple words, common ion effect is defined as the suppression of the degree of dissociation of a weak electrolyte containing a common ion. Many transition metal compounds violate this rule due to the formation of complex ions. For example, copper(I) chloride is insoluble in water, but it dissolves when chloride ions are added, such as when hydrochloric acid is added. This is due to the formation of soluble CuCl2 complex ions.By pulling Ag+ ions out of this equilibrium, the equilibrium must shift to replace them as best it can. i.e. more AgBr(s) must go into solution. The solubility of a slightly soluble salt increases when one of its ions can be changed to a soluble complex ion.Adding the ammonia introduces another equilibrium and we can sum the two equilibrium present.Original EquilibriumAgBr(s) <=====> Ag+(aq) + Br-(aq) Ksp = [Ag+][Br-].

1. The common ion effect is responsible for the reduction in the solubility of an ionic precipitate
when a soluble compound combining one of the ions of the precipitate is added to the solution in
equilibrium with the precipitate. It states that if the concentration of any one of the ions is
increased, then, according to Le Chatelier's principle, the ions in excess should combine with the
oppositely charged ions. Some of the salt will be precipitated until the ionic product is equal to
the solubility of the product. In simple words, common ion effect is defined as the suppression of
the degree of dissociation of a weak electrolyte containing a common ion.
Many transition metal compounds violate this rule due to the formation of complex ions. For
example, copper(I) chloride is insoluble in water, but it dissolves when chloride ions are added,
such as when hydrochloric acid is added. This is due to the formation of soluble CuCl2 complex
ions.By pulling Ag+ ions out of this equilibrium, the equilibrium must shift to replace them as
best it can. i.e. more AgBr(s) must go into solution. The solubility of a slightly soluble salt
increases when one of its ions can be changed to a soluble complex ion.Adding the ammonia
introduces another equilibrium and we can sum the two equilibrium present.Original
EquilibriumAgBr(s) <=====> Ag+(aq) + Br-(aq) Ksp = [Ag+][Br-]
Solution
The common ion effect is responsible for the reduction in the solubility of an ionic precipitate
when a soluble compound combining one of the ions of the precipitate is added to the solution in
equilibrium with the precipitate. It states that if the concentration of any one of the ions is
increased, then, according to Le Chatelier's principle, the ions in excess should combine with the
oppositely charged ions. Some of the salt will be precipitated until the ionic product is equal to
the solubility of the product. In simple words, common ion effect is defined as the suppression of
the degree of dissociation of a weak electrolyte containing a common ion.
Many transition metal compounds violate this rule due to the formation of complex ions. For
example, copper(I) chloride is insoluble in water, but it dissolves when chloride ions are added,
such as when hydrochloric acid is added. This is due to the formation of soluble CuCl2 complex
ions.By pulling Ag+ ions out of this equilibrium, the equilibrium must shift to replace them as
best it can. i.e. more AgBr(s) must go into solution. The solubility of a slightly soluble salt
increases when one of its ions can be changed to a soluble complex ion.Adding the ammonia
introduces another equilibrium and we can sum the two equilibrium present.Original
EquilibriumAgBr(s) <=====> Ag+(aq) + Br-(aq) Ksp = [Ag+][Br-]