paghat wrote:

With any extended exposure, the carbonic acid in Coke dissolves iron, not
just the rusty bits.

Sorry, no. Carbonic acid (a reducing agent) reacts with rust (ferric
oxide) to form ferrous iron, which is water-soluble. It does not react
with elemental iron. Though, if you leave carbonic acid (in water
solution) in contact with iron for an extended period, with access to
oxygen, the iron will continue to rust, and the rust almost
immediately be reduced by the carbonic acid, giving the appearance the
the iron is being directly attacked. So don't leave your rusty tools
in Coke forever

The "black" coating mentioned in another response (sorry, didn't save
it) is not the return of rust to elemental iron as suggested, but the
formation of a dark iron oxide, Fe3O4, aka gun bluing, though it IS a
protection against further rusting. See
http://www.colamachines.com/howto/Rust_101.htm
(this site also has good summaries of various methods to clear rust,
though it does confuse Coke's very low phosphoric acid concentration
with that of Phosphoric Acid etch baths...)

...Coca Cola syrup delivery vans & trucks have to have
special permits for the transport of highly corrosive materials.

Doubtful; this may be an urban legend, too. Even concentrated Coke
(syrup) is not very acid. The concentrations of phosphoric (a mere 11
to 13 grams per gallon of syrup, or about 0.20 to 0.30% per
snopes.com) and citric acids (even less) in it are quite low, and the
carbonic acid only is present after the syrup is carbonated. So
corrosive, yes, but not "highly", just "barely". A more likely reason
for treating the syrup as a corrosive agent is that even a small
amount of dissoved metal ions would result in a metallic off-taste to
the Coke loss of bucks and reputation are big motivators for big companies!

...The
recurring story that the Highway Patrol uses Coca Cola to clean up the
blood after deadly auto accidents is pure legendry, but fun to imagine.

Yup

For debunking various Coke myths, see
http://www2.coca-cola.com/contactus/...gredients.html
http://www2.coca-cola.com/contactus/...packaging.html

Anita
Northern Harford County, Maryland, USA, USDA zone 6

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