can I ask a not so simple question about CO2?

[0roo0roo]

Originally posted by: videogames101
Use vice-grips to close the bottle.

or use a clamp to keep the bottle deformed to the point where theres little headspace.

 

[CZroe]

Originally posted by: spidey07

Originally posted by: uclaLabrat

Originally posted by: spidey07
No. Since the bottle is bigger there is much more air in the container than before where the CO2 was saturated in solution. The CO2 will move from the lidquid to the now larger volume of air in the container until it is equalized.

All this results in less CO2 in the liquid. A trick is to squeeze the bottle until there is little to no air in it and then cap it, that keeps the gas in the liquid.

Won't work. CO2 concentration in the liquid phase is a function of pressure (henry's law), and squeezing the bottle won't change the pressure. When the pressure increases inside the bottle, it will simply expand.

It does work. Think it through.

When I've tried it, the act of deflating the bottle, capping, moving it to/from the refrigerator, etc disturbs enough dissolved CO2 to inflate the bottle by force. All I did by deflating it was make more room for the CO2 to expand into.

 

[DangerAardvark]

I hear they single-serving sized portions of soda now, that come in aluminum cans. 2L is usually more fluid ounces per dollar, but 6/12 packs aren't too far off. BTW, whoever decided to list the volume of cans in fluid ounces and the volume of bottles in Liters needs to fucking die.

 

[Rubycon]

Squeezing the air out of the bottle LOWERS the internal pressure making the CO2 come out of solution FASTER. It will make the pop go flatter faster but will augment fizzing BEFORE it does.

Surprised it has not been mentioned here but if you REALLY want it to fizz just drop in a Mentos. Diet Coke works best. :laugh:

 

[CZroe]

Originally posted by: Fayd

Originally posted by: MrPickins
You need a fizz keeper.

It's a bottle cap with a pump built in that lets you pressurize the bottle and keeps the CO2 in soln.

Edit: or at least it's supposed to. It can never match the partial pressure of CO2 that the bottle originally had.

if you read the link you posted, it says essentially that the fizz keeper is a joke. it doesnt help keep fizz by more than a few hours at most.

my opinion is drink soda fast. i go through about a 2L bottle a day of soda, so i dont have to worry about it depressurizing on me.

I dunno... I would think that if there is too much pressure to evaporate any more CO2 that it couldn't evaporate more CO2, so it has to have SOME effect, right? Like if the air inside were at 100% humidity for that temperature the rest of the H2O would remain liquid, but I guess the CO2 isn't dissolved into liquid simply because it's cold enough to be a liquid.

 

[Eli]

Originally posted by: spidey07
No. Since the bottle is bigger there is much more air in the container than before where the CO2 was saturated in solution. The CO2 will move from the lidquid to the now larger volume of air in the container until it is equalized.

All this results in less CO2 in the liquid. A trick is to squeeze the bottle until there is little to no air in it and then cap it, that keeps the gas in the liquid.

Whut?

How does that work? Air being above the liquid does not "pull" the CO2 out of solution. If you squeeze all of the air out of a bottle, it's just going to fill that space up with CO2.

If anything, you would think leaving the air in the bottle would help. As CO2 comes out of solution, it increases the pressure in the bottle, preventing more CO2 from escaping the liquid.. no?

 

[CZroe]

Originally posted by: Eli

Originally posted by: spidey07
No. Since the bottle is bigger there is much more air in the container than before where the CO2 was saturated in solution. The CO2 will move from the lidquid to the now larger volume of air in the container until it is equalized.

All this results in less CO2 in the liquid. A trick is to squeeze the bottle until there is little to no air in it and then cap it, that keeps the gas in the liquid.

Whut?

How does that work? Air being above the liquid does not "pull" the CO2 out of solution. If you squeeze all of the air out of a bottle, it's just going to fill that space up with CO2.

If anything, you would think leaving the air in the bottle would help. As CO2 comes out of solution, it increases the pressure in the bottle, preventing more CO2 from escaping the liquid.. no?

Not according to this

 

[Eli]

Originally posted by: CZroe

Originally posted by: Eli

Originally posted by: spidey07
No. Since the bottle is bigger there is much more air in the container than before where the CO2 was saturated in solution. The CO2 will move from the lidquid to the now larger volume of air in the container until it is equalized.

All this results in less CO2 in the liquid. A trick is to squeeze the bottle until there is little to no air in it and then cap it, that keeps the gas in the liquid.

Whut?

How does that work? Air being above the liquid does not "pull" the CO2 out of solution. If you squeeze all of the air out of a bottle, it's just going to fill that space up with CO2.

If anything, you would think leaving the air in the bottle would help. As CO2 comes out of solution, it increases the pressure in the bottle, preventing more CO2 from escaping the liquid.. no?

Not according to this

Which part is saying what I said is incorrect?

Thus the partial pressure of CO2 is substantially reduced, from 2 atmospheres to the partial pressure of CO2 in the Earth's atmosphere, which is approximately 0.0003 atmospheres. In accordance with Henry's Law, the excess CO2 dissolved in the drink comes out of solution. Eventually it reaches a new dynamic equilibrium state, with a much lower partial pressure of CO2 in the headspace and thus a much lower amount of CO2 held in solution.

I believe that is essentially saying what I said. Wouldn't the 0.0003 atmospheres of CO2 in the regular atmosphere be better than nothing in the case of pushing all the air out?

Or... hmm. Is this saying that letting the bottle fill back up with its own CO2 will make it last longer than if it were filled with air? But since there isn't 0.0003 ATM of CO2 pressure from the ambient atmosphere, wouldn't the bottle be filled up with the CO2 from solution + 0.0003 ATM to reach equilibrium?

This is confusing.... lol.

/reads more about Henry and Dalton's laws...

 

[Eli]

Bump for more discussion? I'm curious.

 

[mugs]

Edit: I see what you're saying

 

[destrekor]

Originally posted by: Eli

Originally posted by: CZroe

Originally posted by: Eli

Originally posted by: spidey07
No. Since the bottle is bigger there is much more air in the container than before where the CO2 was saturated in solution. The CO2 will move from the lidquid to the now larger volume of air in the container until it is equalized.

All this results in less CO2 in the liquid. A trick is to squeeze the bottle until there is little to no air in it and then cap it, that keeps the gas in the liquid.

Whut?

How does that work? Air being above the liquid does not "pull" the CO2 out of solution. If you squeeze all of the air out of a bottle, it's just going to fill that space up with CO2.

If anything, you would think leaving the air in the bottle would help. As CO2 comes out of solution, it increases the pressure in the bottle, preventing more CO2 from escaping the liquid.. no?

Not according to this

Which part is saying what I said is incorrect?

Thus the partial pressure of CO2 is substantially reduced, from 2 atmospheres to the partial pressure of CO2 in the Earth's atmosphere, which is approximately 0.0003 atmospheres. In accordance with Henry's Law, the excess CO2 dissolved in the drink comes out of solution. Eventually it reaches a new dynamic equilibrium state, with a much lower partial pressure of CO2 in the headspace and thus a much lower amount of CO2 held in solution.

I believe that is essentially saying what I said. Wouldn't the 0.0003 atmospheres of CO2 in the regular atmosphere be better than nothing in the case of pushing all the air out?

Or... hmm. Is this saying that letting the bottle fill back up with its own CO2 will make it last longer than if it were filled with air? But since there isn't 0.0003 ATM of CO2 pressure from the ambient atmosphere, wouldn't the bottle be filled up with the CO2 from solution + 0.0003 ATM to reach equilibrium?

This is confusing.... lol.

/reads more about Henry and Dalton's laws...

What I'm understanding is that the pump does work, but not as a marvelous device as it is claimed. By pumping regular atmosphere into the bottle, and forcing enough air into the bottle to have a higher pressure that regular atmospheric pressure, it is helping to keep more CO2 in solution by having pressure in the headspace. But since it's not a pure CO2 atmosphere, CO2 still has a lot of room to push out of solution and into the air.
But, by having only regular atmospheric pressure and the normal mix, this allows far more room for the CO2 in solution to push out and equalize the pressure. The issue is, since either case is not a pure CO2 headspace, there is no equilibrium in CO2 pressure that is helping to keep the already present CO2 in solution to stay there.

But, either solution is far better than squeezing out all of the air of the bottle. That creates a state of no outside pressure, even the most minimal, holding the CO2 in solution. Even with the bottle holding its deformed shape, and whatever devices you have to help it do so, there is ample room for CO2 to push out of solution to create equilibrium between the solution and the surrounding environment. Essentially, the lack of air creates a vacuum-like state for the CO2 as it won't stay in solution if there is no internal atmospheric pressure forcing it to.

 

[Gothgar]

gotta go canned for soda.... the plastic bottles flat out way to fast

 

[destrekor]

Originally posted by: mugs
When you push the air out you don't create a vacuum, you reduce the amount of non-soda volume that can be pressurized by the CO2 in the soda

vacuum is a bad word, and even I used it to describe the situation... however, just because it appears there is little room for anything other than liquid, don't be fooled. Remember, the bottle comes with a strong CO2 atmosphere inside, so the bottle has plenty of ability to support more than atmospheric pressure inside. So whatever the shape it is in, the atmospheric pressure inside has a lot of room to increase while still holding the same volume and shape of the bottle. By deforming the bottle and squeezing out the air, all you do is create a state of minimal atmosphere. CO2 still has plenty of room, due to how much pressure can be obtained, to push out and attempt to establish equilibrium between the atmosphere and the solution's internal CO2 pressure.

What I haven't worked out yet is, if by squeezing out the air and deforming the bottle in the process, will this result in more CO2 coming out of solution than if it were left with normal amount of atmosphere in the bottle, or the same.
I'm thinking it won't go flat much quicker than simply leaving the bottle alone with the normal mix of air and bottle shape. So end point - it sure as hell won't slow down the process of the solution going flat, but it might not speed it up in comparison either. So ultimately, it's probably a wash, do it if you like the image, but worthless in practice.