Re: Solvent power of Colas and Sodas - Background Info


"TaylorMX" <ytgy111@xxxxxxxxx> wrote in message
news:1172654495.843220.10600@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
For a school science project I'm testing the solvent powers of various
cola products (and one non-cola carbonated soda). Finding out whether
there's a difference between diet & non-diet, etc.

I've tried to set up the experiment as fairly as possible: I have a
set of old pennies ranging from 1950s to 1960s and I'm going to weigh
them beforehand on a scale that's accurate to 10 milligrams, leave the
coins in various liquids (out of Coca Cola, Coke Zero - sugar free,
Fanta - cola free, and purified water as a control) for 8 hours, then
weigh them again afterwards. I'll use identical glasses, keep them in
the same place (out of the sun to ensure that the heat doesn't speed
up any reactions), the same temperature and the same amount of each
liquid (125mL). I'll also repeat the experiment to ensure reliability.

I need some background information prior to doing my experiment. Could
the artificial sweeteners in the diet soft drink affect it? What about
the carbonation of the water? Should I have another control with just
carbonated water? That kind of thing.

Thanks for your help. Any additional sites or books I might be able to
read would assist greatly.


Don't assume that various types of sweeteners will not have an effect on the
corrosion rate. Glucose is inhibitive in some systems. Ive never tested
the
range of artificial sweeteners.

And, yes, why not test carbonated water as part of the series.

Run at least triplicate samples, and if you are going to use coins, try to
use all of them from similar years (or at least, find out what alloys are
used and when
they have been changed. You might get totally different alloys from pennies
of different
eras). Pennies are not predominately copper now.

You may want to use some mild steel washers from the hardware store to see
what these
drinks will do against iron based metals. If so, dont buy the shiny
washers....and for darn
sure dont use stainless steel.

Whether you use pennies or washers, they need to be clean. You may need to
sand them
first, to remove surface coatings..

I think you may be able to come up with some interesting data for your
school project.





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