LATENT HEAT, NUCLEATION, AND SUPERCOOLED LIQUIDS.

Reheater bags release latent heat and crystalize when they are triggered.  This nicely demonstrates:

1. Latent heat of fusion
2. Need for nucleation (here by shock wave)
3. Existence of liquids at T below the freezing point

The material used here is Sodium Acetate TriHydrate with a freezing point of 58C (w/ nuclei), -10C (no nuclei).  Thus at room temperature it can either be a supercooled liquid or a solid.

Nucleation is activated by clicking the spring loaded trigger button.

Read How It Works