"Blueskies" wrote in message
et...

"Jay Honeck" wrote in message
ups.com...
You know I've been wondering: Does the Alka Seltzer trick really check
to
see if alcohol is present? I'm no chemist, but I wonder if the Alka
Seltzer
is just reacting with the water that most alcohols will attract from
the
moisture in the air.

How about it? Any chemists in the group? If the mogas were blended
with
alcohol with low water content, would the Alka Seltzer fizz at all?
Maybe
the best test is still the "line on the beaker" test.

Well, we've been down this road before, back when the Alky test first
came on the scene. Some chemist here ended up concluding that the
test was valid, but I'm always open to hearing other thoughts on the
matter.

If the danged test DIDN'T work, that could ruin my whole day...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"


Seems to me the best test would be to do the alka seltzer test right
alongside the 'water to the line' test, using the
same fuel sample, preferable a known dirty gasoline sample...


Two of the more knowledgeable contributors have stated that the Alka Seltzer
reacts with the water.

Logically, one could split a fuel sample into two parts and test both.
Then, if the fuel passes the AlkaSeltzer test and fails the "line on the
beaker" test; then Clare and Bob will have been proved correct and we will
have also gained a means to determine that fuel has alcohol added, but has
not absorbed moisture.

However, if the Alka Seltzer fizzes and the combined water and alcohol rises
above the "line on the beaker"; then the fuel will have failed both tests
and nothing at all will have been proved--because, as far as I know, the
"line on the beaker" does not seperately determine the amounts of water and
alcohol in the fuel sample.

Really, the only way that I know to correctly "do the science" is to
purchase a small amount (perhaps a liter) of anhydrous ethanol from a
medical supply and perform a series of tests on a variety of
samples--including samples of known pure and dry avgas and mogas. For the
moment, I am unwilling to undertake the project, and also I believe that
Clare and Bob are correct.

Peter