Hot ice

Hot Ice is the name of a super saturated solution of sodium acetate (NaC2H3O2) and water which means that more molecules are packed between the water molecules than would normally occur at room temperature. At 15oC sodium acetate trihydrate has the perfect temperature to go from liquid to solid in seconds producing heat (exothermic reaction).

NaC2H3O2 + H2O -> NaC2H3O2*3H2O + HEAT

When sodium acetate (solid) is dissolved in hot water (liquid) it becomes supersaturated solutions. When the Hot Ice solution is cooled and triggered by addition of a seed crystal, the dissolved sodium acetate comes out of solution and returns to a solid form. During this transition, the solid sodium acetate (NaC2H3O2) absorbs 3 molecules of water into its crystal lattice, becoming sodium acetate trihydrate (NaC2H3O2*3 H2O).