Answer
The common ion effect is responsible for the reduction in the solubility of an ionic precipitate when a soluble compound containing one of the ions of the precipitate is added to the solution in equilibrium with the precipitate.
Work Step by Step
An example of this is : AgCl it is an ionic substance and, when a tiny bit of it dissolves in solution, it dissociates 100%, into silver ions (Ag+) and chloride ions (Cl¯).