There is a kind of hot water bag that will press the chips inside, and then boil it in boiling water for a whileI want to know the principle
Warm handbag fluid is a supersaturated solution of sodium acetate (CH3COONa). The concentration of supersaturated solution is too high, it is not stable. When we distort the inside of the metal films, produced by a slight vibration will be sufficient to make the solute crystallization becomes more stable solid. However, this process is exothermic, so warm bag began to warm up.
As long as the warm bag into the boiling water for about 10 minutes, condensation of the solute will be dissolved again; this is due to the high temperature, increase of soluble solute. In the process of dissolution of the solute was endothermic reaction, once again become supersaturated solution.
1 175g sodium acetate (CH3COONa) into a beaker containing 50mL water:2 dissolve sodium acetate in beaker with hot tub;3 pour the solution into a fresh bag and add a piece of twisted metal
