Crystallization of sodium acetate. When sodium acetate trihydrate (CH3COONa 3H2O) melts at 58C, it releases bound water (water of crystallization) and dissolves in it. When the solution is allowed to cool slowly, it becomes supersaturated. If a nucleation centre (ex., a small piece of solid sodium acetate, left frame) is formed or introduced, it causes the solution to crystallize back into solid sodium acetate trihydrate (centre and right frames). This process is exothermic and releases heat. It found its use in consumer heating pads. | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Giphotostock |
Taille de l’image : | 7100 px × 3525 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |