OMG! Now I understand why we invaded Iraq!

[Amianthus]

Ami actually knows a lot of facts. It is the meaning of them that always eludes him.

Ahh, so you're saying that I don't lie all the time, as you do?

[Michael Tee]

<<As I said, water does not boil at 190 degrees at any atmospheric pressure below the summit of Mt. Everest. And it won't do so, there, either.>>

As I recall, the issue depended on was what was the atmospheric pressure on the surface of the liquid when the cap was suddenly removed, and the surface rapidly decompresses - - which nobody seems to know.  Furthermore, you were talking about the boiling point of water and I was talking about the boiling point of a colloidal suspension of coffee in water; apples and oranges.  Furthermore, if I accepted 190 degrees as the actual boiling point, it was for the sake of the argument only, so as not to engage in a side issue.  The real point I was making was that it was - - and remains - - a theoretical possibility for a liquid to boil over at less than its normal boiling point under conditions of sudden decompression - - as any idiot would recognize if he or she ever unscrewed the cap of a ginger ale bottle.

<<So, tell me, where was the McDonalds located? The Moon?>>

Yours, maybe.  Stella's was somewhere in the U.S.A.

[Amianthus]

As I recall, the issue depended on was what was the atmospheric pressure on the surface of the liquid when the cap was suddenly removed, and the surface rapidly decompresses - - which nobody seems to know.

Oh, I know. First, when I was majoring in chemistry in college, we did some of these experiments. Besides that, the physical properties are all known, and I looked them up in my Handbook of Chemistry and Physics. The pressure differential on a coffee cup would be the equivalent of about 80 pounds. Have you found a Styrofoam coffee cup that would withstand 80 pounds yet?

Furthermore, you were talking about the boiling point of water and I was talking about the boiling point of a colloidal suspension of coffee in water; apples and oranges.

And if you knew any chemistry, you would that suspensions and solutions increase the boiling point, not decrease it. Basic chemistry. You're gonna get your lowest boiling point with a pure liquid. That's actually the point of adding salt to boiling water when cooking - it increases the boiling point a degree or two for better cooking.

Furthermore, if I accepted 190 degrees as the actual boiling point, it was for the sake of the argument only, so as not to engage in a side issue.  The real point I was making was that it was - - and remains - - a theoretical possibility for a liquid to boil over at less than its normal boiling point under conditions of sudden decompression - - as any idiot would recognize if he or she ever unscrewed the cap of a ginger ale bottle.

And if you knew any chemistry, you would know that the ginger ale bottle reaction is due to a chemical reaction, and not "boiling" in any way.

A chemical reaction that cannot occur in a cup of coffee.

Sorry, you have no facts on your side in this argument.

Go talk to a chemistry professor at your local college so he can explain it to you, as I suggested years ago.

[sirs]

the physical properties are all known, and I looked them up in my Handbook of Chemistry and Physics. The pressure differential on a coffee cup would be the equivalent of about 80 pounds. Have you found a Styrofoam coffee cup that would withstand 80 pounds yet?....if you knew any chemistry, you would (I'm assuming the word "know" goes here) that suspensions and solutions increase the boiling point, not decrease it. Basic chemistry. You're gonna get your lowest boiling point with a pure liquid. That's actually the point of adding salt to boiling water when cooking - it increases the boiling point a degree or two for better cooking.....if you knew any chemistry, you would know that the ginger ale bottle reaction is due to a chemical reaction, and not "boiling" in any way.  A chemical reaction that cannot occur in a cup of coffee.  Sorry, you have no facts on your side in this argument.

OUCH......Ami with a major spanking

[Amianthus]

which nobody seems to know.

Oh yeah, and this statement right here is total BULLSHIT.

YOU don't know. Fortunately, YOU are not the repository for all human knowledge, even though you'd like everyone to think so.

[Michael Tee]

More bullshit from the master of BS - - first of all, 80 lbs pressure is a lotta fuckin pressure and you have produced no evidence whatsoever to prove that a liquid decompressing rapidly from 80 psi would not boil over.  So your whole bullshit argument should be ended right there.  Particularly as my argument was expressly stated to be in theoretical terms, but even putting it into your experimental terms, you have produced no data whatsoever to back it up.

The colloidal suspension argument is bullshit.  Raised or lowered by the colloidal suspension, the fact remains that the boiling point of whatever's in the cup will be reached at a lower temperature if the atmospheric pressure is decreased.  My sole point in mentioning that we were dealing with a colloid was that you had probably no experimental or published data to support your boiling point or atmospheric pressure figures.

The ginger ale phenomenon is NOT a chemical reaction, it is the physical change of state occasioned by dissolved CO2 gas coming out of solution (i.e. boiling) solely because of a sudden decrease in the atmospheric pressure caused by the removal of the cap - - analogous to the removal of the lid of the coffee cup.

You are a perfect example of a little knowledge being a dangerous thing - - a college chemistry course enables you to deny the basic principles of physics.  Sorry, but BS is BS.  I'm glad you are able to convince sirs, though - - he's a fitting acolyte for your chemistry lectures.

[Amianthus]

More bullshit from the master of BS - - first of all, 80 lbs pressure is a lotta fuckin pressure and you have produced no evidence whatsoever to prove that a liquid decompressing rapidly from 80 psi would not boil over.

I don't have to. I never said 80psi, that was your bullshit. I said that it would be 80 pounds total. Last time I checked, a Styrofoam cup was more than one inch square of surface area.

So your whole bullshit argument should be ended right there.  Particularly as my argument was expressly stated to be in theoretical terms, but even putting it into your experimental terms, you have produced no data whatsoever to back it up.

Don't need to. I provided the source of the data - my copy of the Handbook of Chemistry and Physics. Unfortunately, that text is not provided on-line, so you'll have to go look it up in the library. Or buy a copy - I think they're running about $150 a piece right now.

The colloidal suspension argument is bullshit.  Raised or lowered by the colloidal suspension, the fact remains that the boiling point of whatever's in the cup will be reached at a lower temperature if the atmospheric pressure is decreased.

No duh. I even calculated the approximate pressure differential required, I believe it was 450 millibars.

My sole point in mentioning that we were dealing with a colloid was that you had probably no experimental or published data to support your boiling point or atmospheric pressure figures.

Sure they're published. As I said, the Handbook of Chemistry and Physics has the physical constants at various pressures for pure water. The modification of the boiling point is (first year chemistry) modified by 1 degree centigrade for every mole of impurities. A mole, BTW, (again, first year chemistry) is Avogadro's number of molecules. What do you think, chemists are idiots? They've been working on this stuff for centuries.

The ginger ale phenomenon is NOT a chemical reaction, it is the physical change of state occasioned by dissolved CO2 gas coming out of solution (i.e. boiling) solely because of a sudden decrease in the atmospheric pressure caused by the removal of the cap - - analogous to the removal of the lid of the coffee cup.

Actually, the carbonic acid / water balance in soda water is held steady by the pressure of the container. When the container is opened and the pressure released, the carbonic acid breaks down into water and carbon dioxide. The equilibrium expression for carbonated water is H₂CO₃ <=> CO₂ + H₂O.

Oh yeah, boiling is not "a gas coming out of solution." It is the conversion of a substance from it's liquid state to it's gaseous state. It's got nothing whatsoever to do with "a gas coming out of solution."

You are a perfect example of a little knowledge being a dangerous thing - - a college chemistry course enables you to deny the basic principles of physics.  Sorry, but BS is BS.  I'm glad you are able to convince sirs, though - - he's a fitting acolyte for your chemistry lectures.

Actually, "major in chemical engineering with a minor in physics" is a more accurate statement. My father is so embarrassed that I decided to work with computers for a living instead of being an engineer - he said at the time that computers were a "passing fad."

[Amianthus]

Oh yeah, before you respond Mikey, I'd like to clarify something.

In the last post, when I said "first year chemistry" I wasn't talking about college chemistry. All of that stuff you were assumed to know before starting college chemistry. That stuff is first year high school chemistry.

[Michael Tee]

Well, you're right about boiling - - - it IS the vaporization (change of state) from liquid (water in this case) to gas (water vapor.)

I will go back to my theory:  the liquid is hot and the surface is under pressure from water vapor produced by heat and trapped between the liquid surface and the inside of the lid and the cup.  The pressure inside the cup is greater than the atmospheric pressure outside.  The pressure inside the cup raises the boiling point of the liquid above what it would be at ambient outside atmospheric pressure.  The lid is removed suddenly.  Water vapor escapes from the cup, lowering the atmospheric pressure inside the cup at least to the ambient outside atmospheric pressure and possibly temporarily lower because of heated air and vapor being sucked out in the wake of the escaping vapor.  As the pressure drops rapidly on the liquid, the boiling point also diminishes and boiling occurs.

I don't see that as fanciful in the least.  There's no data on the atmospheric pressure inside the cup, particularly after a lid is suddenly removed and it's a theoretical possibility.  I don't say that's what happened but there is no scientific argument that it couldn't happen, absent the data on boiling points, pressure inside the cup and the effect of sudden removal of the lid and escape of air and vapor.

[domer]

No wonder I've stuck to the humanities.

[Michael Tee]

This is pretty basic stuff.  Given Ami's background, I wouldn't want to get  into anything complicated with him.

[domer]

No, what I mean is that I simply don't have the drive to understand things like this; in other words I find it boring.

[Plane]

"...which nobody seems to know..."


No MT, actually Amianthus is right, a stirofoam coffee cup cannot withstand enough pressure differential to cause the effect you are talking about, if you ever find one that seals at all you have found an unusual one .

If you were to place a bit of dry ice into a styrofoam cup and place a lid on it the CO2 would sublime and raise the pressure on the cups interior untill the lid would come off with a pop, this pop would represent less than one half of one LbPSI.


Lets assume that when the cup was filled with hot coffe the liquid was ten degrees cooler than boiling, then the lid would be applied, a well designed lid will vent , but assumeing that the lid would not vent ,the sealed hot liquid and vapor would tend to develop a reduced pressure as it lost heat and the vapor condensed .


I recall my mother canning tomato , beans , jelly etc.  The usual procedure is to bring the liquid in the jars up to a high tempreture and then apply a lid loosely , when the heat is removed the contraction of the vapor and air and the liquid within the jar causes the lid to pop down in a vacuum seal.

There are a few things that can be done that seem like the effect that you are speaking of , but they canot be done with a coffee urn.


Check out what happens when you drop three "Mentos" into a two liter diet drink.

http://video.google.com/videoplay?docid=-1450915772177922792

Note that water holds almost no disolved gas at 190 degrees.

Water brought to the boiling point will not necessacerily boil if undisturbed. Then when it is disturbed it can boil suddenly.

http://www.snopes.com/science/microwave.asp


Note that this couldn't be done with a coffee urn .

[sirs]

"...which nobody seems to know..."

No MT, actually Amianthus is right, a stirofoam coffee cup cannot withstand enough pressure differential to cause the effect you are talking about, if you ever find one that seals at all you have found an unusual one .....If you were to place a bit of dry ice into a styrofoam cup and place a lid on it the CO2 would sublime and raise the pressure on the cups interior untill the lid would come off with a pop, this pop would represent less than one half of one LbPSI.....Lets assume that when the cup was filled with hot coffe the liquid was ten degrees cooler than boiling, then the lid would be applied, a well designed lid will vent , but assumeing that the lid would not vent ,the sealed hot liquid and vapor would tend to develop a reduced pressure as it lost heat and the vapor condensed.  There are a few things that can be done that seem like the effect that you are speaking of , but they canot be done with a coffee urn.

OW, Plane goes and fact-slaps the other side of Tee     

[Plane]

Recently we had a problem in a hangar where the F-15s are repaired.


Someone put some dry ice into two liter bottles and left them in the garbage , this caused loud bangs .

Which brought in security to question everyone in the hangar.

Glad I was not involved , everything is a federal case here.