Why+does+metal+rust?


 * __WHY DOES METAL RUST?__**

Answer the question below, append new answers to the top of this page. _ __Response 1:__ Iron oxide has a lower free energy than do iron and oxygen. Just as a ball will roll downhill because it has a lower free energy at the bottom of the hill than at the top, iron will combine with oxygen - essentially 'rolling down a chemical reaction hill'. The reason things like water, salt, acids and other chemicals cause iron to rust faster, is that these substances act as // catalysts // to the oxidation reaction.
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[|http://wiki.answers.com/Q/Why_does_iron_rust#ixzz1jTFjIMYJ]

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