AAMC FL Practice Exam

What happens to solute when a solution becomes saturated?

1. It dissolves faster

2. It begins to precipitate

3. It decreases in concentration

4. It evaporates

The correct answer is: It begins to precipitate

When a solution becomes saturated, it reaches the maximum concentration of solute that can be dissolved at a given temperature and pressure. At this point, any additional solute added to the solution cannot remain in solution and will start to form solid particles, leading to precipitation. This phenomenon occurs because the solvent molecules can only accommodate a certain number of solute particles at equilibrium. When the saturation point is exceeded, the excess solute cannot be kept dissolved and thus begins to precipitate out of the solution and forms a solid. This concept is crucial in understanding solubility, equilibrium, and chemical reactions involving solutions, illustrating the dynamic balance between the dissolved solute and the solid state when dealing with saturation levels.