[johnsholto]

Could someone explain to me why iron is not dissolved by concentrated sulfuric acid? (eg concentrated sulfuric acid can be stored in an iron barrel)

I understand that it has something to do with passivity in that, I think, Fe is oxidized to FeO2. But why does this exactly happen? (and why not in diluted acid)

Thanks

 

[AWK]

read
http://www.chemicalforums.com/index.php?topic=38230.0