Provide an example of the effect of common ions on the solubility of different ionic compounds.

Common ions can affect the solubility of ionic compounds by decreasing or increasing it.

When two ionic compounds containing the same ion are mixed, the concentration of that ion in the solution increases. This can affect the solubility of the compounds. For example, when calcium chloride (CaCl2) is added to a solution containing calcium carbonate (CaCO3), the concentration of calcium ions increases. This causes the solubility of calcium carbonate to decrease, as the excess calcium ions combine with carbonate ions to form insoluble calcium carbonate.

On the other hand, when two ionic compounds containing different ions are mixed, the concentration of each ion in the solution decreases. This can increase the solubility of the compounds. For example, when sodium chloride (NaCl) is added to a solution containing silver nitrate (AgNO3), the concentration of both sodium and nitrate ions increases, while the concentration of silver ions decreases. This increases the solubility of silver nitrate, as the excess nitrate ions combine with silver ions to form soluble silver nitrate.

The effect of common ions on solubility can also be seen in the common ion effect. This is when the presence of a common ion in a solution decreases the solubility of a slightly soluble salt. For example, the solubility of lead chloride (PbCl2) is decreased when hydrochloric acid (HCl) is added to the solution, as the concentration of chloride ions increases.

In conclusion, the presence of common ions can have a significant effect on the solubility of ionic compounds, either decreasing or increasing it depending on the specific ions involved.