tito-o-mac - 1-7-2007 at 00:28
An extremely silly but crazy idea. And one look at it done by the mythbusters sparked a new record breaking event(10.4 metres). Anyone thought of any
new ideas of breaking that record? Modifying the surface structure of a mentos to increase nucleation, resulting in a fizzier explosion?
12AX7 - 1-7-2007 at 06:50
The limiting factor is the pressure that a bottle can produce given a typical carbonation. It would be interesting to know how much pressure is made
under those conditions, but it's probably no more than 30 PSI or so: whatever the partial pressure turns up to be. (It's interesting that CO2's
partial pressure is so sensitive to surface area. A bottle at rest comes to equilibrium with somewhat more than atmospheric pressure, but adding
nucleation to a sealed bottle -- shaking it -- causes the pressure to rise noticably.)
Tim
unionised - 1-7-2007 at 10:30
It would be interesting if the partial pressure of CO2 over its solution varied with the area because it would solve the world's energy problems.
Since talk of free energy machines is frowned upon here I won't go into details. The pressure doesn't change with area- the rate at which equilibrium
is attained does.
This report shows that the pressure is quite often rather greater than 30 PSI and in some cases can reach nearly 4 times that.
http://www.dti.gov.uk/files/file21474.pdf
12AX7 - 1-7-2007 at 11:45
Then why does an unopened bottle of soda, having been in storage for an extended period of time, gain pressure when you shake it?
The partial pressure would have to be constant with area, being that's its definition, but that leaves much to be desired in explaining this
phenomenon.
Tim
chemkid - 1-7-2007 at 12:31
mentos is now selling little tubes around packs of mint mentos so you can stack the mentos in them put a toothpick in the bottom and put it over a
soda bottle and pull out the tooth pick.
Find something more poruous then mentos to use. More nucleation sites? Maybe some sort of abrasive stone. For some reason stell wool comes to mind. I
may try it out in my lab, if i was there
Chemkid
[Edited on 2-7-2007 by chemkid]
[Edited on 2-7-2007 by chemkid]
tito-o-mac - 1-7-2007 at 22:13
can extra strong mint help? Just don't use any fruit flavoure one. It's coating is rather smooth
chemkid - 2-7-2007 at 14:23
Extra strong mint? Never heard of it but i doubt it. It is probably just packed with more sugar.
tito-o-mac - 10-7-2007 at 01:35
They sell 'em in asia. How about modifying the soda or something? No one seems to think about it. How do you get a fizzier soda?
unionised - 10-7-2007 at 09:17
"Then why does an unopened bottle of soda, having been in storage for an extended period of time, gain pressure when you shake it?
"
How did you measure it?
I suspect that extra strong mints have more mint in them, rather than more sugar.
12AX7 - 10-7-2007 at 14:37
I measured it by squeezing. To the best of my recollection (hmm, it's been suprisingly long since I had a two liter bottle or something in hand...
may have to go get some!), it's stiffer / more turgid when shaken.
16MillionEyes - 31-7-2007 at 18:30
If you figure out a way to introduce the nucleation catalyzist (it doesn't have to be mentos, it could be anything that does the same job example
sugar) in a powdery form it might increase the rate of evaporation of the CO2.
You also have to keep in mind that no matter how much nucleation catalizist you add to the coke the pressure will always be limited to the amount of
CO2 dissolved in the bottle so pressure would only be dependent on the rate of gas nucleation and volume (which if it's kept close is a constant of
approximately X-2L of the liquid (using a 2L bottle obviously) where X is the extra space on the bottle when filled). So as a whole the maximum
pressure would be the amount of gas evolved contained in an X volume and this will determine the maximum area it will cover.
Of course, you might apply ideal gas law (P1V1=P2V2) but this is inappropriate as most likely the gas has gone through compression (I'd suggest using
the real gas law equation) and has reached solubility equilibrium.
From there it's a matter of finding derivatives of the presure, volume proportionality with force as valve is released etc etc. It's a whole physics
cake from there so perhaps the easiest way to try to brake the record (if that's not already the maximum) is by trial and error.
[Edited on 31-7-2007 by __________]