|MadSci Network: Chemistry|
Jessica: That is a very interesting question. The metling of ice requires the addition of heat in order to liberate the water molecules that are tied up together in the form of ice. By adding heat the molecules increase their motion allowing them to break out from the bonds (called Hydrogen bonds) keeping them together. The result is the liquid form of ice: water. Blowing air to ice may result in an increase of the temperature near the ice surface therefore allowing the ice to melt faster than if no air were being blown at it. Adding salt also help in the melting of ice, but at a signifianctly lower rate. The process is a bit different here, since the melting is due to the fact that water molecules on the surface of the ice start to dissolve the salt. These molecules, on the surface of the ice, are bound to the rest of the ice from one "side" only if you will, the other "side" is pointing at the air. So surface molecules are not "in a cage" like the those molecules inside the ice, therefore they are similar to liquid molecules. These surface molecules will then start to dissolve the salt and in the process they are released from the ice surface and become liquid. This process is slower that than of ice melting by blowing air. Jessica I hope this answers your question
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