Can you carbonate a liquid with a 500 ml air tank?

[1683cadder]

I know it seems like a dumb question, but I really need this answered. I am doing a science experiment (google sci fair) that needs carbonic acid, so to make this acid I need to keep the container in as much pressure as possible in order to force more carbon dioxide into solution and therefore make more carbonic acid. I plan to use 100ml of solution and about .1 mol of dry ice. I don't want to use 2 L bottles because they seem too weak. Is it safe to do it in an air tank? I'm not trolling; this is a legitimate question.

[SoftwareBug2.0]

I think you're good, but I would check it yourself using the universal gas law: pv=nRt. (pressure)(volume)=(amount in mols)(gas constant)(absolute temperature)

pressure=max pressure for your vessel (I know some of the tanks are 240psi, but check yours)
volume=500ml-100ml
n=.1
r=(depends on what units you use for everything else)
t=I would solve for this. This would be the temerature at which your vessel would reach its rated pressure.

I got that you'd need a temperature of like 800 kelvin to get up the rated pressure, but do the math yourself, and I know that I would stand behind a door or something if I knew somebody was going to try this.

[1683cadder]

Thanks. I did the math myself and I found I was well below the 500 psi burst rating for Andy mark part. Is it safe to go past operational pressure(150psi)? The temperature is about room temp

[EricH]

Originally Posted by 1683cadder

Is it safe to go past operational pressure(150psi)?

Yes and no.

Operational pressure is 125 psi (rated). Burst pressure is 500 psi (rated). (Note: All numbers are for the AM 500 ml plastic tanks.) There is a difference in what each is, what it's designed for, even how it's calculated. I'm going to scratch the surface.

Operational pressure says, quite simply, you can run at this pressure for a long, long time without any issues expected. Burst pressure is the pressure at which you'll have a failure in the event of a sudden high-pressure event. The fact that they're both "rated" pressures means that they can actually take higher pressures, but can't necessarily be counted on above their ratings. If you're going above the rated capacity on anything, check the math a few times to verify you'll be OK.

There is also a safety factor built in, too--but it's built into the rating, so it's not really applicable.

Short version: If your pressure is fairly low, you can probably get away with exceeding the rated pressure--but I wouldn't try using it for FRC use again. Do the math--if you really want to, I'm sure we can step through stress calculations for an AM 500ml cylinder, or try to.

[1683cadder]

Thanks for the replies!