The phenomenon of crystallisation comes from the dehydration of sodium ethanoate trihydrate to anhydrous sodium ethanoate. In fact, the trihydrate substance, the one we want for our warmers, liquefies if we heat it above 58°C. On the other hand, the anhydrous substance only liquefies at 324°C. So when you remove the water from a molecule, PAF! It becomes anhydrous and solidifies instantly, because we're well below 324°C!
Français
English
Deutsch
Español
Italiano
Português