The ____ is the limit to which a solute can be added to a solvent.

The saturation level is the limit to which a solute can be added to a solvent.

A solution with the maximum possible amount of solute is saturated. If a solution contains less than the maximum amount of solute, it is unsaturated. When a solution is saturated and excess solute is present, the rate of dissolution is exactly equal to the rate of crystallization.