Übereinsättigung

Übereinsättigung refers to a state where a solution contains more dissolved solute than it would under normal equilibrium conditions. This phenomenon occurs when a saturated solution is cooled or when the solvent evaporates very slowly, allowing the solute to remain dissolved beyond its normal solubility limit. The excess solute does not precipitate out due to the absence of nucleation sites or disturbing factors like vibrations.

This metastable state is unstable and can be easily disrupted. Introducing a small crystal of the solute, known as a seed crystal, or agitating the solution can trigger rapid crystallization of the excess solute, returning the solution to its stable saturated state. Übereinsättigung is a crucial concept in various fields, including chemistry, physics, and materials science, and has practical applications in processes like crystallization for purification and crystal growth. It is also observed in everyday phenomena such as the formation of sugar crystals on the rim of a jam jar. Understanding and controlling übereinsättigung is vital for achieving desired product characteristics and optimizing industrial processes.