The difference between saturated and supersaturated solution, the difference between saturated solut

The difference between saturated solution, unsaturated solution and supersaturated solution must first start with the dissolution process of the substance. When a solid is dissolved, the basic particles on its surface, molecules or ions, gradually leave the solid surface and distribute to all parts of the solvent due to interaction with solvent molecules. At the same time, the opposite process is taking place: the solute particles are constantly moving in the solution, and when they touch the surface of the solid, they may be attracted again, detached from the solution (precipitated from the solution), and returned to the solid.

If, given a certain amount of solvent and a certain temperature, the number of molecules (or ions) entering the solution from the solid solute and the number of molecules (or ions) returning to the solid from the solution per unit time are equal, then a dynamic equilibrium is established

At this time, a certain solute dissolved in the solution can no longer be increased, and the solid is no longer dissolved on the outside, and the concentration of the solution has reached the saturation value at this temperature, that is, it has reached the saturated solution state. So, a saturated solution is a solution when the dissolved solute and the excess unsoluble solute reach a dynamic equilibrium. At a certain temperature, the amount of solute contained in a saturated solution is constant.

To prepare a saturated solution at a certain temperature, an excess solute must be added to the solvent so that a part of the excess solute remains in the solution.

An unsaturated solution is a solution that continues to dissolve without reaching equilibrium. That is, the solution when the amount of solute contained in the solution is less than the amount of solute in the saturated solution at this temperature.

Whereas, a supersaturated solution is a solution in which the amount of solute contained in the solution is greater than the amount of solute in the saturated solution at this temperature (i.e., it exceeds the normal solubility). No solid solute must be present in the solution to produce a supersaturated solution.

The reason why supersaturated solutions can exist is because solutes do not easily form crystalline centers (i.e., crystal nuclei) in solution. Because each crystal has a certain arrangement rule, there must be a crystal center, so that the solute particles that were originally moving in disorder can be gathered and arranged in the order unique to this crystal. Different substances have different degrees of difficulty in achieving this regular arrangement, and some crystals take a considerable amount of time to produce crystalline centers on their own, so the supersaturated solution of some substances still seems relatively stable.

But in general, the supersaturated solution is in an unbalanced state, is unstable, if it is vibrated or added to the solute crystal, the excess solute in the solution will precipitate and become a saturated solution, that is, converted into a stable state, which shows that the supersaturated solution is not as stable as the saturated solution, but there is still a certain stability. Therefore, this state is also called a mesostable state.

To prepare a supersaturated solution, it is necessary to prepare a saturated solution at a higher temperature, and then slowly filter it to remove the excess unsoluble solute and slowly reduce the temperature of the solution to room temperature. At this time, the concentration of the solution has exceeded the saturation value at room temperature and has reached a supersaturated state.

Saturated and supersaturated solutions of the same substance of the same volume, the mass of the supersaturated solution should be large, and the same mass of the substance is added to the two solutions respectively, and the solute will be precipitated into an e-saturated solution in the supersaturated solution,,, which is an unstable state...

The solution has only saturated and unsaturated states. There is no such thing as oversaturation.

Saturated solution refers to the state in which a certain substance is dissolved in a certain solvent to reach the maximum amount at a certain temperature.

Supersaturated solution refers to the solubility of solute at a certain temperature and pressure, when the concentration of solute in the solution has exceeded the solubility of the solute at that temperature and pressure.

The solution where the solute has not yet precipitated is called supersaturation. Supersaturated solutions are unstable, and if the solution is stirred, vibrating, rubbing against the walls of the vessel, or by throwing solid "seeds" into the solution, the excess solute in the solution will immediately crystallize and precipitate.

The reason for the existence of supersaturated solutions is that the solutes in this solution do not easily form crystalline centers (called crystal nuclei). To crystallize, a crystalline center must be formed in the solution so that the solute particles in the solution can be arranged in order around the crystallization center to form a crystal precipitation.

Saturated solution: It refers to the fact that at a certain temperature, a certain dose of solvent cannot continue to dissolve the solute, which means that the concentration of the solution remains unchanged, and the saturated solution must be at a specific temperature and a certain dose, targeting the same substance.

Supersaturated solution: refers to the solution at a certain temperature and pressure, when the concentration of solutes in the solution has exceeded the solubility of the solute at the temperature and pressure, and the solute still does not precipitate, this phenomenon is called supersaturation.

Difference: Neither saturated solution nor supersaturated solution can continue to dissolve solutes, the difference is that the concentration of supersaturated solution is greater than the concentration of saturated solution at the same temperature and pressure.

Supersaturated solutions are easily converted into saturated solutions, and saturated solutions are more stable than supersaturated solutions. A saturated solution is a critical state of a supersaturated solution.

Supersaturated solution bending ear refers to the solution at a certain temperature and pressure, when the concentration of solute in the solution has exceeded the solubility of the solute at the temperature and pressure, and the solute has not yet precipitated. This phenomenon is called supersaturation. Supersaturated solutions are unstable, and if the solution is stirred, vibrating, rubbing against the walls of the vessel, or by throwing solid "seeds" into the buried solution, the excess solute in the solution will immediately crystallize and precipitate.

The reason for this is that the solute in this solution does not easily form a crystalline center (called crystal nucleus). To crystallize, it is necessary to form a crystallization in the solution to make the solute particles in the solution arranged in order around the crystal center to form a crystal precipitation.