If it is saturated with a solid solute, you would expect some of the solid to precipitate out - as long as the solid could find a surface to nucleate on. If it is saturated with a gas, you would expect more gas to dissolve into it as long as it was still in contact with the saturating gas in the gas phase.
A supersaturated solution contains more solute than predicted at a given temperature. This can happen when a solution is prepared with more solute than can normally dissolve in that solvent at that temperature, creating a metastable state where the excess solute remains dissolved until disturbed.
When the amount of solute is equal to the amount of solvent, the solution becomes saturated. This means that no more solute can dissolve in the solvent at that temperature. Any additional solute added will remain as undissolved solid at the bottom of the container.
Cooling air below the dew point will result in the water in that air coming out of solution to deposit itself on surfaces. We call that dew. Certainly as the temperature continues to fall, it may even cause rain (if it isn't too cold).
If a room were cooled to the dew point, the air temperature would reach the point at which water vapor in the air would begin to condense. This would result in the formation of dew on surfaces like windows, walls, and floors.
Crystallisation
If a hot saturated solution is cooled quickly, the solubility of the solute decreases with temperature, causing excess solute to precipitate out of solution. This rapid cooling can result in the formation of larger crystals or a higher amount of crystals in the solution.
If a saturated solution of copper chloride is cooled, the solubility of the compound will decrease, causing excess copper chloride to precipitate out of the solution in the form of solid crystals. This process is known as crystallization.
As the KNO3 solution cools, solubility of KNO3 decreases with temperature, leading to the formation of excess KNO3 crystals. These crystals will start to precipitate out of the solution as it cools. If the cooling continues, more crystals will form until the solution becomes saturated at a lower temperature.
When a crystal of potassium nitrate is added to the saturated solution as it is cooled, it will act as a seed crystal for the excess solute to come out of solution and crystallize. If no crystal were present, the solution may remain supersaturated, meaning it contains more solute than it can naturally hold, leading to potential spontaneous crystallization or precipitation with any disturbance.
the concentration of this solution is going to reduce.< Lets assume that the solution is comprised of water and salt> Then the water at a certain temperature begins to evaporate unlike the salt. at the end of the process, yes we agree that the solution has finally come to a room temperature, but concentration was lost during cooling. I mean that the solution becomes less concentrated
If it is saturated with a solid solute, you would expect some of the solid to precipitate out - as long as the solid could find a surface to nucleate on. If it is saturated with a gas, you would expect more gas to dissolve into it as long as it was still in contact with the saturating gas in the gas phase.
If you decrease the temperature of the saturated solution of NaCl in water, the solubility of NaCl will decrease and the excess salt will start to precipitate out of the solution as solid crystals. This is due to the lower temperature reducing the amount of salt that can dissolve in the water, leading to a supersaturated solution.
the solute can re-form as a solid
A solution can be dilute and saturated if there is a small amount of solute relative to the amount of solvent, making it dilute, but all of the solvent has already dissolved the maximum amount of solute possible at that temperature, making it saturated. This can happen when the solute has low solubility in the solvent or if the temperature decreases after the solution has been prepared.
They dissolve until the solution is saturated.
A supersaturated solution contains more solute than predicted at a given temperature. This can happen when a solution is prepared with more solute than can normally dissolve in that solvent at that temperature, creating a metastable state where the excess solute remains dissolved until disturbed.