Sciencemadness Discussion Board - Liquid gasses

Liquid gasses

Scratch- - 10-3-2005 at 14:59

I have a list of gasses here that might be neat to ampoule while liquid. If you put a liquid gas in a container and seal it up it should remain a liquid provided it cant break the container from the pressure and theres not enough room for it to totally expand and become a gas. So if you had some ampoules made of thick thick glass you should be able to contain alot of the higher BP gasses. But the problem is that the only kind of ampoules I can find are those that are sold for containing medicines to keep them sterile, these would be good maybe for holding gasses with a BP higher than 0 degrees but IDK besides that. Does anyone know where to get ampoules with thicker glass? Also a few more interesting gasses wouldnt hurt.

(NOTE: some of these gasses would be hard to ampoule, like SO3, and some would be downright insane, like F2.)

Temp (C)............Composition
58.7.........................Br2
44.8.........................SO3
21.2.........................NO2
0..............................Ice and water (Cooling solution)
-7.............................NH3NO3 and water (Cooling solution)
-10.06......................SO2
-21...........................Ice and saturated NaCl solution (Cooling solution)
-33.34......................NH3
-34.06......................Cl2
-35.4........................HI
-40...........................Ice and saturated CaCl solution (Cooling solution)
-66.7........................HBr
-78...........................Dry ice and acetone (Cooling solution)
-85.06......................HCl
-88.6........................N2O
-108.1......................Xe
-151.7......................NO
-153.4......................Kr
-183.17....................O2
-185.86....................Ar
-188.2......................F2
-195.86....................N2
-195.86....................Liquid nitrogen (Cooling solution)
-246.06....................Ne
-252.8......................H2
-268.94....................He

An ampoule of liquid helium would be really neat.

Sources:
Gas BPs: http://chemfinder.cambridgesoft.com/
Cooling solutions: https://www1.fishersci.com/education/resources/eqtip06.jsp

[EDIT: Corrected the BP of HI and removed O3, which decomposes when liquified]

[Edited on 3/11/2005 by Scratch-]

[Edited on 3/11/2005 by Scratch-]

neutrino - 10-3-2005 at 16:21

Quote:

Originally posted by Scratch-
If you put a liquid gas in a container and seal it up it should remain a liquid provided it cant break the container from the pressure and theres not enough room for it to totally expand and become a gas.

Any way you seal it, the gas will exert the same outward pressure—its vapor pressure. Since this increases with temperature, this means that you will have a hard time ampouling any of the lower-boiling gasses without an explosion. Another problem: some of these gasses would become supercritical fluids at room temperature, leaving you without a clearly defined liquid-gas boundary. This shouldn't be much of a problem, though, as this is almost always at 25+ atm.

All of this aside, I have thought about ampouling liquid chlorine but can’t do it without dry ice. My idea was as follows: seal one end of a short glass tube and extrude the other end into a capillary so the liquid could be pipetted in. Chill with dry ice, add liquid chlorine, and seal. So far, I have only been able to do this with difluoroethane (Bp. -25*C), but chlorine should be doable, only having a vapor pressure of around 3-4 atm at room temperature.

A word of advice on this: when sealing the ampoule, make sure that the liquid inside it doesn’t heat up. A slight increase in temperature of a liquid near its boiling point causes a very large increase in vapor pressure. This inevitably bursts the bubble of molten glass at the top of the ampoule (where it’s being sealed), ruining it. To avoid this, cool the liquid down a lot, seal the ampoule very quickly, use a very thin and hot flame, get some glassworking experience, and if possible, ensure a distance of at least ¾” between the ampoule and liquid.

A thought about storage: could the ampoule be stored in a block of transparent plastic? It’s hard to describe, but I’m thinking of those blocks the bugs in museums are always sealed in.

12AX7 - 10-3-2005 at 16:27

Just mind the critical temperature, above which it cannot be compressed into liquid form.

F2 can be stored gaseous for a little while (see www.theodoregray.com), under the pressure to keep it liquid or supercritical might be a bit harder though...

Tim

chemoleo - 10-3-2005 at 16:40

Transparent plastic - hmm. Having had some experience with it, it always takes some time to harden (i.e. polyester resin). The more catalyst one adds (MEKP), the faster the hardening, but it produces a big temperature spike. This is not good for the gas, and also it causes cracks. Foreign objects in resin also require slow hardening, to avoid cracks (the object has different expansion coefficients than the resin). It'd be tricky to do, but possibly worthwile if done well!

a_bab - 10-3-2005 at 16:41

Most of the gases in your list are next to imposible to "ampoule".
With chlorine it is possible though. What you need is gases with a scritical temperature superior to the room temperature, and a "liquification" presure with a value less then 5 atm let's say, so that the ampule will resist to the presure.

Liquid chlorine is an oily, green liquid...Very interesting to see I bet.

Scratch- - 10-3-2005 at 16:52

Yeah the lower temperature ones, but what about most of the ones above the dry ice/acetone mixture? I was thinking that those should be doable, but I need to do more research. For ampouling I was thinking that I could just almost seal the ampoule and letting it cool before I put the liquid in, similar to neutrino's procedure.

BromicAcid - 10-3-2005 at 20:57

Ummm... Bp of hydrogen iodide is actually -35 C. Why would you want to ampule SO3 anyways?

Scratch- - 10-3-2005 at 21:20

Not sure, I hear its a pretty canary yellow as a liquid. I actually had trouble with the hydrogen iodide, there were several conflicting sites.

Dangerous and corrosive liquid gasses just seem to appeal to me, for no apparent reason. I'll have to devise an effective storage method for these so they get neutralized if they ever get out (Out of some kind of inner container that is). Perhaps an inner sealed ampoule cushioned in a larger outer container partially filled with a hydroxide for the more acid forming gasses.

a_bab - 11-3-2005 at 02:03

You don't seem to know enough chemistry yet. There is a thing involved here, which is called the "critical temperature". As 12AX7 stated, above this temperature, no matter how great the pressure is, the gas cannot be liquified anymore. Such gases are hydrogen, oxygen and nitrogen to name a few. They all have critical temps lower than 30 degrees C. In an oxygen tank, the contents are gaseous even at 300 atm. Knowing that, you first have to filter your gases using this criteria, as the ampoule, even if made of steel will explode once you pass the critical temperature, and then look for low pressure liquification gases.

There are two ways to liquify a gas: by the means of pressure or temperature.
Once you ampouled liquid nitrogen or helium let's say (which I doubt you'll ever see, as it's the melting temperature is almost 0 Kelvin), it doesn't mean that your stupid ampoule will witstand the thremendous pressure caused by the expansion of the boiling gas.

Study a little bit the law of the gases, so you can understand some basic notions, and then do your research concerning values like boiling/melting point for gases.
A good starting point might be here

[Edited on 11-3-2005 by a_bab]

Scratch- - 11-3-2005 at 06:59

And you dont seem to be a good judge of chemistry knowledge. Yes I know what critical temperature is, thats what my research is about.

Perhaps I should rephrase the question in my second post to:

"Yeah the lower temperature ones, but in general arent most of the ones with a BP above the dry ice/acetone mixture also have a critical temperature high enough to liquify?"

When I said it would be neat to ampoule liquid He I was joaking.

mick - 11-3-2005 at 13:38

If you ever want to open an old ampoule the best thing seems to be freeze it solid, dri-ice or liquid N2. Otherwise use gloves, goggles and a shield because the thing might go bang. Stuff in ampoules can discolour which could mean some thing is happening in there.

mick

a_bab - 11-3-2005 at 14:38

Alright, sorry for the flame. I am always very rough. My mood is kinda angry usually.
Just gor your info, I am also very keen about liquid gases. An I posees 9 ampoules with SO3. (they are used as fumigant, you know, for making clouds of H2SO4 smoke)

Still, the bromine is a liquid at room temperature.

BromicAcid - 11-3-2005 at 16:54

Bromine may be a liquid at STP but we all know how readily it furmes so usually at my school we use ampules of it with 2.5 ml each. Storing under water or H2SO4 also works but having ampules around is just convient.

cyclonite4 - 11-3-2005 at 21:22

SO3 may not even need to be pressurised.
It has 3 crystalline modifications with melting points of 17, 33, and 67 degrees.

BromicAcid - 11-3-2005 at 21:25

Not to mention that without a polyermisation inhibitor your SO3 will really be reluctant to volatize in the near future.

a_bab - 12-3-2005 at 00:02

He started the thread with "I have a list of gasses here that might be neat to ampoule while liquid", and bromine (a liquid) is the first one in the list.

Scratch- - 12-3-2005 at 12:16

Bromine probably wouldnt be liquid very long where I live

. I just want to collect liquid gasses because I think they would be neat, not for reagents. Can you describe your liquid SO3 a_bab? Can you also describe these crystals cyclonite4?

a_bab - 12-3-2005 at 14:22

My SO3 is not liquid but a solid absorbed into some sort of earth thing. You can have liquid SO2 in an ampoule since it's easy to liquify.

[Edited on 12-3-2005 by a_bab]

Scratch- - 12-3-2005 at 16:04

Good idea, SO2 would be good for getting experience with liquid gasses. I'm still trying to find someplace to get ampoules, but I guess I could just use large diameter glass tubing.

neutrino - 12-3-2005 at 18:02

If you want experience, I suggest you start out with bromine (this teaches you the basics, especially not letting the liquid heat up) and the gas in compressed air dusters (mine is HF<sub>2</sub>C-CH<sub>3</sub>, but the composition varies).

[Edited on 13-3-2005 by neutrino]

cyclonite4 - 12-3-2005 at 18:10

I'm not saying they are crystals, Scratch.
What I'm saying is SO3 has three different cyrstaline modifications (alpha, beta and gamma, with melting points of 62, 33, and 17 degrees celcius).

I've heard that SO3 is supposed to be a fuming solid or liquid, so having alpha or beta SO3 is most likely.

EDIT: Just to help you understand, here is a definition of crystallinity: The degree to which polymer molecules are oriented into repeating patterns.

[Edited on 13-3-2005 by cyclonite4]

Scratch- - 12-3-2005 at 18:50

Oh, I was thinking of a different definition of crystaline:

"Solid material composed of regularly repeating atoms, ions, or molecules that form defined patterns or lattice structures."

Is this correct? That makes me think its crystals. I see what you mean though.

Bromine might be a good gas to start with but I cant seem to find any NaBr to make it from, the local stores dont seem to carry it and I dont think theres a pool supply store nearby. I'll try the compressed air, I have some of that. Thanks.

cyclonite4 - 12-3-2005 at 20:06

I can understand what you mean. I find it a bit confusing too. Basically, it helps to think of a crystal as a polymer.

Your definition of crystal, I beleive, is quite correct. I was defining crystallinity.

Good luck anyways.

sparkgap - 13-3-2005 at 00:06

Both your definitions are consistent, cyclonite4 and Scratch-. The key word is "ordered". As long as whatever is comprising the substance in question is in a regular (or fairly) pattern, it is a crystal.

And BTW, crystals can be liquid, too.

You may want to take a look at your digital displays the next time.

sparky (^_^)

patu - 17-3-2005 at 22:45

I managed to ampoule a small amount of liquid chlorine in a durham tube. The tube is only 50 mm long and 6 mm wide so it was tricky. I started off by filling a 250 ml volumetric flask with chlorine gas from a hcl kmno4 reaction. I then cut a square piece of duct tape and poked a hole with a nail in the middle. I then pushed the durham tube through it having the sticky side of the tabe on the same side as the open end of the tube. I then put the tape with the tube sticking out on top of the flask with the chlorine. i then inverted the whole unit and inserted only the tube part into a cut off coke can filled with dry ice. i used a ring stand and clamps to hold up the flask. after about five minutes i lifted up the whole thing and saw a small amount of yellow liquid at the bottom of the durham tube. i immediately put the tube back under the dry ice. i removed the flask and the tape and left the tube in the dry ice. the tube was sticking out enough for me to torch it shut. the first two i did had small holes that didnt close so all of the liquid chlorine leaked out within five minutes of it warming up. the last one fully closed because i still have liquid chlorine in it and it has been a day. Me happy!!!!

Saerynide - 18-3-2005 at 02:47

Good job. Can I see a picture?

I've been wanting to see one for a long time

chloric1 - 18-3-2005 at 03:06

Wow! THats great news! Good work! Look like even I can do this! Maybe if you could find a high pressure check valve, regulator and a tank to hold it, you could have portable elemental chlorine!

chloric1 - 18-3-2005 at 03:46

Hey patu,

I forgot to ask, did you take special measures to dry the chlorine or did you
condense it straight from the reaction flask?

patu - 18-3-2005 at 13:07

I didnt dry the chlorine. But as the flask sat in the dry ice, any water that had been in the flask immediatly condensed then froze on the sides. this prevented much from entering the tube. i will try to upload a picture soon. but for now i can describe what it looks like. the liquid chlorine is very fluid, easily moving up and down the sides of the tube and then all settling back down at the bottom quickly. it's a dark yellow color and very clear. the remainder of the tube is filled with chlorine gas that has the distinctive greenish yellow tint.

garage chemist - 19-3-2005 at 10:14

Here you can see a picture of liquid chlorine:
http://www.seilnacht.com/Lexikon/17Chlor.htm