How is a supersaturated solution made?

Answer 1

A saturated solution is prepared by dissolving as much solute as the solvent can hold (usually at room temperature).

If the conditions are changed such as increasing the temperature or pressure, then more of the solute can be dissolved.

For a gas (like Carbon dioxide) a closed soda bottle or can contains a supersaturated solution of Carbon dioxide in water (or soda). When the pressure is released, the excess Carbon dioxide come out of solution and forms bubbles.

For a solid like salt or sugar, saturating an aqueous solution at an elevated temperature will usually cause it to supersaturate when the temperature to returned to room temp.

Supersaturated solutions are usually unstable and anything which will cause crystallization or equilibrium of the solution will happen as soon as possible.

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Answer 2

Supersaturated Solutions

Answer 3

The general gist is: You saturated the solution with solute (ex. salt), heat the solvent (ex. water) to a relatively high temperature before adding more solute, then bring the entire mixture back down to room temperature slowly so the extra solute doesn't become undissolved.