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help please!?!?!


T man831

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I have been trying to preform the "HOT ICE" experiment lately and it just has not been working, and i would love some advice on what i might be doing wrong or if its just not possible...:confused:

 

HOT ICE experiment ---->

:confused:

 

can some one pleas explain what is happening here? so i might have a better understanding of were i am going wrong.:confused:

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FYI, from http://en.wikipedia.org/wiki/Sodium_acetate

 

Sodium acetate is also used in consumer heating pads or hand warmers and is also used in "hot ice". When sodium acetate trihydrate crystals (melting point 58 °C) are heated to around 100 °C, they melt. When this melt cools, it gives a supersaturated solution of sodium acetate in water. This solution is capable of supercooling to room temperature, well below its melting point, without forming crystals. By clicking on a metal disc in the heating pad, a nucleation center is formed which causes the solution to crystallize into solid sodium acetate trihydrate again. The bond-forming process of crystallization is exothermic, hence heat is emitted.[1] [2][3] The latent heat of fusion is about 264-289 kJ/kg.[4]

 

Which confirms what yourdad said, that you have to supersaturate the solution (though the wiki note that in order to melt them you have to heat them to 100 ºC even though the melting point is 58 ºC is contradictory)

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