How can a supersaturated solution be prepared from a saturated solution formed at room temperature?
by adding more solute as well as heating it
A saturated solution cannot dissolve anymore of the solute at the given temperature.
But if we heat the given solution, it will start dissolving more solute.
Once we cool it down to the original temperature, the excess solute dissolved will precipitate or crystallize out. As this happens, heat is given off.