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Common Ion Effect

Definition

The common ion effect refers to the decrease in solubility of an ionic compound when an ion similar to those already present is added to the solution.

Analogy

Imagine you're at a concert and the venue is already packed with fans (ions). If more fans (common ions) try to enter, it becomes harder for them to find a spot because the venue (solution) is already filled with similar fans.

Related terms

Le Chatelier's Principle: The principle that states if a system in equilibrium is disturbed by changes in determining factors, such as temperature, pressure, or concentration of components, the system will shift its equilibrium position so as to counteract the effect of the disturbance.

Precipitation Reaction: A reaction where an insoluble solid (precipitate) forms from two aqueous solutions.

Ionic Compound: A compound composed of positive and negative ions.