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#11
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Testing the Testing of Mogas
"Jay Honeck" wrote in message oups.com... Plop-plop, fizz-fizz... :-) In a previous thread I outlined the new (vastly more convenient) "alka-seltzer method" of testing your mogas for both ethanol and water -- but (for those who missed it) here it is again: 1. Tap a few ounces of suspect gas into a cup 2. Drop 1/4 of an alka-seltzer into the gas 3. If no fizz, no alcohol or water is present, and the gas is "good" The question was/is: Is it chemically valid to expect alka-seltzer to fizz in the presence of alcohol? Mary (with her minor in chemistry) and I (with my English degree that allows me to, er, write about this) devised the following empirical test: Part I: 1. Purchase a bottle of 95% pure isopropyl (rubbing) alcohol. While it's not ethanol, Mary determined that the chemical make-up is similar enough for this test. 2. Pour a few ounces into a cup. 3. Add 1/4 tablet alka-seltzer to the alchohol. 4. Observe results. ** Sure enough, the tablet instantly starting fizzing.** Part II: 1. Go to gas station we always buy our gas from. 2. Pump a few ounces into a cup. 3. Add 1/4 tablet alka-seltzer to the cup. 4. Observe results. ** Sure enough, the tablet just sat there -- no fizz.** Part III: 1. Add some alchohol to aforementioned cup of gas, approximating a 10% mixture. 2. Observe results. ** Sure enough, the tablet instantly started fizzing, verifying that it WOULD fizz if there were alcohol in the gas. ** There are a few questions yet to answer 1. Since isopropyl alchohol is 95% pure, that means that it is 5% water. Is the tablet fizzing only because of the 5% water? 2. However, even if this were the case, would it not also be true that the presence of ethanol in the car gas would ALSO introduce water, and thus fizz the alka-seltzer regardless? In other words, is it irrelevant that the alka-seltzer might only be fizzing because of the water, if water always accompanies alcohol in gas? Either way, the fizzing would indicate the presence of water OR alcohol, or just alcohol that is "saturated" with water -- both of which would indicate a "No Buy". Right? -- Jay others have already commented on the alka seltzer chemisty, but a simpler and quantitative way of measuring how much alcohol is in the fuel is to simply mix it with water. Try 9 parts of fuel to 1 part of water in a graduated cylinder. the alcohol will migrate to the water phase so you will see an increase in the height of the water layer at the bottom and a decrease in the height of the fuel layer if there is significant amount of alcohol.. terry |
#12
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Testing the Testing of Mogas
And for all you wannabe chemists out there... Denatured alcohol
(ethanol plus a bit of methanol) is available everywhere... I have a quart stting in front of me on my desk I picked up at the hardware store... I use it for cleaning my glasses, camera lenses, etc.. Get 100 cc of gasoline, add 10 cc of denatured alcohol from your favorite Home Depot, etc., add 1/4 tab of "plop, plop, fizz, fizz" and observe... If it fizzes then you know that the test is valid as your mixture is "gasohol"... denny - minor in B.S., major in Obfuscation... |
#13
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Testing the Testing of Mogas
I believe a number of different chemicals are used to denature ethanol.
Benzene for one. Denny wrote: And for all you wannabe chemists out there... Denatured alcohol (ethanol plus a bit of methanol) is available everywhere... I have a quart stting in front of me on my desk I picked up at the hardware store... I use it for cleaning my glasses, camera lenses, etc.. Get 100 cc of gasoline, add 10 cc of denatured alcohol from your favorite Home Depot, etc., add 1/4 tab of "plop, plop, fizz, fizz" and observe... If it fizzes then you know that the test is valid as your mixture is "gasohol"... denny - minor in B.S., major in Obfuscation... |
#14
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Testing the Testing of Mogas
"Skywise" wrote in message ... "Crash Lander" wrote in : Not at all a scientific type person, so this may be a dumb question, but is there any way to evaporate the water out of the isopropyl alcohol without burning off the alcohol, or is the evaporation point of the alcohol lower than that of the water? If so, could you evaporate the alcohol out of the water, and collect the pure alcohol that way? Crash Lander Having just read up on isopropyl alcohol the other day for other reasons, I can help answer this.... [warning! I may have gone overboard on the info] snip good stuff... ...which are dissolved...in a glass of water. As the tablets dissolve, the acid and bicarbonate react vigorously producing carbon dioxide gas Oh No, Greenhouse Gas Warning, Global warming! Brian -- http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html Sed quis custodiet ipsos Custodes? Thanks Brian. This is the neatest part of usenet. Someone out there has the answer. Al G |
#15
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Testing the Testing of Mogas
others have already commented on the alka seltzer chemisty, but a simpler
and quantitative way of measuring how much alcohol is in the fuel is to simply mix it with water. Try 9 parts of fuel to 1 part of water in a graduated cylinder. the alcohol will migrate to the water phase so you will see an increase in the height of the water layer at the bottom and a decrease in the height of the fuel layer if there is significant amount of alcohol.. Thanks, but this is precisely the test procedure I'm trying to eliminate. Carrying water around in "The Mighty Grape", and sitting at my gas station pumps while pouring water and gas into a beaker, and shaking it, is just too much of a pain. People in line behind me must really wonder what the HECK I am doing! :-) If I can get away with simply dropping a tablet in the beaker, I will (a) eliminate the water, and (b) speed things up considerably. -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
#16
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Testing the Testing of Mogas
"d&tm" wrote in message
... others have already commented on the alka seltzer chemisty, but a simpler and quantitative way of measuring how much alcohol is in the fuel is to simply mix it with water. [...] I'm guessing you didn't see the earlier thread, but...your procedure is where this all started. Jay even referenced it in his previous Alka-Seltzer thread, when he wrote: we have used the "water/gas/shake" test to verify that there is no ethanol present. I find this method to be rather imprecise and quite a pain So, here's a gentle "yes, we already know" in reply to your suggestion. Jay is attempting to come up with a test that is more foolproof, easier, less messy, whatever. Personally, I'm not sure that even if the Alka-Seltzer method works, it's superior to the water-mixing method. After all, if you test by mixing water, you just have gasahol with some water in it. You can even strain the water out using a GATS jar if you want to use it (if the test is positive, then in something that can tolerate ethanol, of course...like your car). If you test it with Alka-Seltzer, now you've contaminated your fuel with an Alka-Seltzer tablet. At the very least, you've a fuel-soaked tablet you need to dispose of, and I'm not sure that the fuel is usable at that point, ethanol or not. Just because the tablet didn't fizz, that doesn't mean there aren't bits of it in the fuel. Assuming this doesn't already exist, I think it's only a matter of time before you can buy a fuel testing kit that is either just strips you dip into a fuel sample, or drops you drip into a fuel sample, and which tells you with a change of color whether there is ethanol or not in the fuel. Either the water mixing OR the Alka-Seltzer just seems too unwieldy to me to be practical in the long run. Pete |
#17
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Testing the Testing of Mogas
In article ,
Skywise wrote: the isopropanol solubilizes the water in the gasoline. solubilizes.... Now that, is an interesting word! |
#18
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Testing the Testing of Mogas
In article om,
"Jay Honeck" wrote: Carrying water around in "The Mighty Grape", and sitting at my gas station pumps while pouring water and gas into a beaker, and shaking it, is just too much of a pain. People in line behind me must really wonder what the HECK I am doing! :-) If I can get away with simply dropping a tablet in the beaker, I will (a) eliminate the water, and (b) speed things up considerably. After performing the test, and the fizzing commences, pour the contest of the test tube into your tank. When they ask you what you are doing, tell them you have discovered a magic tablet that allows you to put water and the tablet in your tank and make your own gasoline. What they saw you doing was testing to make certain you had the correct proportions. |
#19
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Testing the Testing of Mogas
"Peter Duniho" wrote If you test it with Alka-Seltzer, now you've contaminated your fuel with an Alka-Seltzer tablet. At the very least, you've a fuel-soaked tablet you need to dispose of, and I'm not sure that the fuel is usable at that point, ethanol or not. Just because the tablet didn't fizz, that doesn't mean there aren't bits of it in the fuel. I would take an alka seltzer tablet, break it up and mix it in some fuel as good as you can, and try it in your lawn mower. I'll bet that it wouldn't miss a beat. If an engine can take that, surely a funnel with a filter screen will catch all the significant chunks. As far as the dud soaked alka seltzer tablet goes, Jay needs to soak one in pure gas, and see if it will still alert on alcohol a few days later. If it does, all he has to do is keep a small jar around to keep the soaked tablet in, to use for the next purchase. -- Jim in NC |
#20
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Testing the Testing of Mogas
Assuming this doesn't already exist, I think it's only a matter of time
before you can buy a fuel testing kit that is either just strips you dip into a fuel sample, or drops you drip into a fuel sample, and which tells you with a change of color whether there is ethanol or not in the fuel. Either the water mixing OR the Alka-Seltzer just seems too unwieldy to me to be practical in the long run. Yeah, the ultimate would be a kit not unlike our pool-testing kit at the hotel. Dip a little bit of litmus paper (or whatever it's called) into the gas, and watch for a color change. Invent one, Edison! :-) -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
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