http://pubs.acs.org/cen/science/88/8804sci3.html?featured=1
This article is about the chemical processes involved in hand warmers commonly used by many people during winter activities. The idea of the hand warmer originated from the Japanese who would use hot stones. However, the technology involved today is much more advanced. Hand warmers today are made of semi-permeable cloth pouches which typically contain iron powder, salt, water, an absorbent material, and activated carbon. When the plastic packaging is removed, the contents of the pouch mixes with the oxygen in the air to essentially produce rust (iron oxide Fe2O3) which is an exothermic reaction. Hand warmers are just one use of this sort of chemical reaction, other uses include the transportation of tropical fish and more recently different uses in the medical field.
Posted by Will Black
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Who knew rust can actually be an advantage?
ReplyDeleteBefore,reading this I only saw rust as an unwanted reaction. I was only exposed to the numerous methods of preventing rust such as galvanization, chromium plating,sacrificial protection, etc.
the hand warmer sounds appealing especially in winter times like this.
-putri matahari
I actually had no idea how hand warmers worked until I read this. It's very interesting. When I first read this I was wondering why people would shake the contents in the hand warming bags if the heat is produced by interacting with oxygen rather than the mixing of the chemicals inside the hand warmer, but I'm guessing it's so that all the molecules interact with the oxygen to produce more heat, rather than only the molecules on the surface.
ReplyDelete-Dora V.