Ask A Scientist Chemistry Archive

name         Marcia F.
status       other
age          40s

Question -   Is there a qualitative chemical test for rust determination?  Sometimes 
discolorations on steel can be rust, other  times, not.  What is the best chemical 
determinant?
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Marcia,

As you may know, steel is not pure iron. Rather, it is likely to be an alloy which may 
contain variable amounts of metals such as chromium, manganese, molybdenum, and others. 
In light of that complexity, there is no simple qualitative test that will distinguish 
which metal in the mix has oxidized to "rust." Discolorations produced by oxidative 
attack on steel are likely to be blends of iron oxide/s and other metal oxides as 
well.

Regards,
ProfHoff 772
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