This would be an incredible party trick. Not many people could remain unimpressed with “hot ice,” but it’s actually based on some fairly simple science.
“Hot ice” is actually sodium acetate trihydrate. This substance appears white and crystalline at room temperature, but melts into a clear liquid at 58°C. If the liquid is then supercooled (cooled below its melting point without changing to a solid), it will quickly become solid when it is disturbed.
The reason this substance is sometimes called “hot ice” is because its temperature actually increases the “icier” it becomes in appearance. This is because the crystals that look like ice are actually present at room temperature, not at the supercooled-liquid state that precedes the reaction.
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