Sciencemadness Discussion Board

Experiments with liquid Nitrogen...

chemoleo - 3-3-2005 at 17:57

I am in a somewhat lucky position, having access to liquid N2 anytime.

Can anyone think of interesting experiments to do with it? For instance, I remember the Na solvation experiment which happily dissolves in liquid ammonia. Are there similar experiments like this, i.e. unexpected solutions of compounds in N2(l)?
Of course there are many reactions that can be done with extremely unstable compounds, unfortunately they are often hazardous (such as oxides of halogens, halogen-halogen compounds, compounds in a very high oxidation state that'd normally decompose, and so on).
Or are there compounds that can be only made at very low temps, and yet persist at RT (unlikely from a thermodynamic perspective)?

Any ideas? I haven't gotten further than freezing ethanol and various liquids.
It's quite interesting to see that ethanol becomes as viscous as glycerol when it reaches its freezing point. On the fingers, it nearly feels sticky (like glycerol) which doesn't last long of course because it heats up.
Another experiment was to accidentially freeze the fingertip of my thumb - I noticed nothing until a sharp pain hit me. By that time, the tip of my thumb was solid and whitish. Once defrosted, it hurt a little, stung, and after a few days the skin started to peel off. I was lucky it didnt go very deep.
For that matter, I know that warts and such are removed with liquid nitrogen, it seems to work as seen with my little thumb experiment!

Oh, and freezing glacial acetic acid, or diethanolamine with it worked very well - two liquids that'd normally refuse to crystallise at 4 deg C or so.


Any input/suggestions welcome (except those that involve bodily parts ;) )

Twospoons - 3-3-2005 at 19:29

How about Making high TC superconductor

The_Davster - 3-3-2005 at 19:35

Not chemistry related but I read something a while back about speeding up your computer by making a liquid nitrogen cooling system. If I remember correctly it was called overclocking.

neutrino - 3-3-2005 at 20:29

Overclocking isn’t necessarily cooling the processor. Rather, it’s modifying the processor’s instructions in some way to run faster. This generates heat which tends to fry the chip, which is why you need a good cooling system. I have heard of making chips run faster by cooling (or something like that), but I think only works with a few of them.

Back to playing with the nitrogen: a couple of fun things to do with it are: 1.make ice cream (you get a nice, smooth ice cream because a.the nitrogen vaporizes very quickly, preventing big crystals from growing and b.the nitrogen arêtes (not sure what the right word here is) the cream), 2.make dry ice, 3.spill it onto a metal table and watch the drops flying around on a cushion of nitrogen gas 4.put it on your tongue (the same principle), and lots of other stuff.

You may want to look here.

The_Davster - 3-3-2005 at 20:43

Ah thanks for clarifing that for me neutrino.

I have made liquid nitrogen icecream before and it is superior to most icecreams I have tasted.

Make liquid oxygen...I am sure you can figure out many uses for this yourself.;)

JohnWW - 4-3-2005 at 02:05

Liquid nitrogen is used in minor surgery, to remove warts, moles, and small benign tumors, by freezing them hard and cracking them off.

As for high-temperature superconductors, only the recently-discovered yttrium-barium-copper mixed oxides and similar ceramic compositions which have lattice vacancies and a metal in more than one oxidation state (2 and 3 in the case of copper) are superconducting at as high as liquid nitrogen (boils at 77ºK) temperatures.

[Edited on 4-3-2005 by JohnWW]

I am a fish - 4-3-2005 at 09:08

mick - 4-3-2005 at 13:12

Liquid nitrogen is used in minor surgery, to remove warts, moles, and small benign tumors, by freezing them hard and cracking them off.

From personal experience I think that is dri-ice. Genital warts appear and need to be sorted out, after all the pills and other stuff freezing with dri-ice worked. They need sorting out because they have been linked cervical cancer, herpes etc. If they were going to sort it out with liquid nitrogen I do not think I would have turned up.

mick

With liquid nitrogen you can make slush baths and know it is that temperature. I think if you fill a metal container with it, liquid oxygen might condense underneath it.

mick
edite to add


[Edited on 4-3-2005 by mick]

alchemie - 4-3-2005 at 19:02

Quote:
Originally posted by I am a fish

You could cool polymers to below their transition-to-glass temperatures. At 77K, rubber tubing will shatter rather than bend.


This is fun. The rubber tubing shatters just like glass when you hit it.

If you do this with a latex glove it looks like you are breaking french fries (the thin ones). Just freeze one, throw it to the ground and stomp on it and you'll see what I mean.

runlabrun - 4-3-2005 at 22:02

You could make what has been said to be the worlds best iced cream!!!
http://www.polsci.wvu.edu/Henry/Icecream/Icecream.html
and many more
http://www.google.com.au/search?hl=en&q=liquid+nitrogen+...
Apparently the liquid N2 makes it ice crystal free so your result is perfectly smooth ice cream and also i read its very fluffy due to the aeration action of the N2 bubbling off....

Mmmmm sounds nice...
-rlr

Skinflint - 5-3-2005 at 22:52

I have a 25 liter LN2 tank that I fill up sometimes. It really does make great ice cream. I can tell you a lot of fun activities to do with liquid nitrogen, but it is hard to think of scientific applications. An interesting thing to do is to break open an incandecent light and put the filament into the LN2 and light it up. The filament just being near the surface of liquid nitrogen will protect it from oxidation.

It is also a lot of fun to spit liquid nitrogen. If measure out a teaspoon or so and put it in you mouth then quickley spit it out, it make a huge amount of smoke. Very impressive and not as dangerous as it sounds. A teaspoon swallowed will just make you burp a lot.

You could use it to liquify methane and use that as a solvent, or study the magnetic properties of cryogenically cooled copper. It would be interesting to freeze a bit of mercury in a mold of a nail and pound it into a board. Hg is supposed to be as hard as steel at those temperatures. Thats all the ideas I can come up with.

JohnWW - 6-3-2005 at 00:43

with regard to Chemoleo's orignal post, it is quite likely that alkali metals would react with liquid N2 to form, in succession, the anions •N=N-, -N=N-, -•N-N--, and N---, similarly to the gas-phase reaction.

Aluminum and magnesium

chloric1 - 6-3-2005 at 06:42

I hear these metals are extreamely fragile at liquid nitrogen temperatures. You could pound these with a heavy hammer and when you have shards/granules then you can ball mill these for a week or so with stearin.

Also, you could condense or freeze equilmolar amounts of NO and NO2 to form unstable N2O3 and directly neutralize with NaOH, or KOH or any other strong alkali to get the pure nitrite.

neutrino - 6-3-2005 at 06:43

In the link I posted, a couple of people were talking about freezing tanks of butane, cutting them open, and playing with the butane ice inside.

unionised - 6-3-2005 at 07:54

Here's a tale about what NOT to do with it.
http://pharyngula.org/index/weblog/comments/aaiieee_dont_eve...

sparkgap - 6-3-2005 at 08:32

:o:o:o:o:o:o:o:o:o:o:o

Jeez, urban legend or not, it's wacko to take a swig of something that liquefies below 0 °C !!!!!

That was dumb.

Oh, and chloric, ballmill with stearin? Why would a glyceride be needed for ballmilling a metal?

sparky (~_~)

P.S. I wonder how molten agar (or gelatin) would behave when poured in liquid N<sub>2</sub>? :D

neutrino - 6-3-2005 at 09:00

I read that one before, but don’t remember the scars or hospital visit. What it said happened was that he mixed up holding liquid nitrogen on his tongue and drinking it. Not too smart, but possible.

garage chemist - 6-3-2005 at 09:31

Neutrino, that link was good. I haven't read it entirely, but got to the solid butane experiments and pictures.
I wonder if propane can also be used? Because propane is much cheaper than butane and available in 5kg- tanks.
It'll surely liquefy, but I'm not sure if it will freeze.

I also have access to liquid nitrogen at any time, but its expensive (2,50€/liter) and I have to buy several liters.

I always wanted to make liquid ammonia, dissolve sodium in it and add an iron catalyst to make NaNH2 (which directly gives NaCN on heating with charcoal).
But LN2 is way too cold for this (the ammonia would solidify) and dry ice isn't available.

Liquid oxygen is great fun to play with , I once did the cigarette-in-LOX experiment in school and it burned rapidly with a fascinatingly bright purple flame. At the end, the LOX soaked cotton filter deflagrated as if it was guncotton.
A piece of charcoal soaked in LOX exploded on lighting, scattering white hot charcoal pieces over the entire room and causing our teacher to dispose of the remaining LOX to stop further experimenting.

sparkgap - 6-3-2005 at 09:50

Methinks propane would solidify. ChemFinder says propane melts @ -187.778 °C, while liquid N<sub>2</sub> boils @ ~ -195 °C.

sparky (^_^)

garage chemist - 6-3-2005 at 09:58

Good, I'll try the propane thing when I get some LN2.

I also read that many colored substances change colour when cooled with LN2. Sulfur, for example, becomes white as chalk. Bromine first solidifies and then the color changes to a light yellow-orange.

Lead, at room temp, is soft, but at LN2 temp it is hard and elastic as steel. A bell made of lead rings like it was silver when cooled and hit with a metal rod.
Maybe you can hammer a nail made of soldering lead/tin wire into a piece of wood?

I once had some molten chocolate on a carpet and it was sticky and impossible to remove. After pouring LN2 on it, it could easily be scraped off.

[Edited on 6-3-2005 by garage chemist]

The_Davster - 6-3-2005 at 10:01

Just thought of another idea, make liquid ammonia and then dissolve alkali metals. If you were so inclined you could then use the solution of alkali metal in ammonia to make the azide of the metal dissolved.

EDIT: This will not work as pointed out by sparkgap. I do not know why I was thinking ammonia would still be liquid at these temperatures.:(

[Edited on 6-3-2005 by rogue chemist]

sparkgap - 6-3-2005 at 10:20

garage chemist already mentioned that ammonia will freeze at the temperature of liquid N<sub>2</sub>. :D

You may want to take a look at ChemFinder or any chemical handbook if you believe the contrary.

sparky (^_^)

Saerynide - 6-3-2005 at 11:31

Quote:

I once had some molten chocolate on a carpet and it was sticky and impossible to remove. After pouring LN2 on it, it could easily be scraped off.

Your carpet fibres didnt shatter and break off? :o

garage chemist - 6-3-2005 at 12:42

No, the fibers didn't shatter, they remained flexible. Don't ask me why, though.

I have a pair of plastic tweezers for handling a superconducting pellet. They also remain flexible at LN2 temperatures. It must be a special kind of plastic...

chloric1 - 6-3-2005 at 14:07

Quote:


Oh, and chloric, ballmill with stearin? Why would a glyceride be needed for ballmilling a metal?


Basically sparky, when these metals get in a finely divided state they may become pyrophoric. THe stearin is merely a precaution that can eeasily removed with toluene and next with ether. The grinding media would be steel balls or lead if you where paranoid about sparks. Lead may contaminate though.

sparkgap - 7-3-2005 at 03:54

chloric:

I see. Lubricant of sorts. Gracias for the enlightenment. :D

garage chemist:

Apparently, your carpet fibers and tweezers have a glass transition temperature well below that of liquid N<sub>2</sub>. :) On this, I can't find a comprenhensive table of glass transition temperatures of polymers, and from the tables I've seen on the web, just about every common polymer becomes brittle @ liquid N<sub>2</sub> temperatures.

sparky (^_^)

mick - 7-3-2005 at 14:06

Making liquid ammonia with liquid N2
Just a guess
Dry ammonia boils at about -33oC and freezes at -78oC. Dri-ice and acetone is about -78oC and condenses ammonia as a liquid fairly easily, some still gets out though. I thought of isopropanol or ethyl actate which freeze a round -85oC (some paint thinners should would work). Turpentine freezes at -60oC to -50oC but it might not cool the ammonia down fast enough to liquify most of it.
You could use the liquid nitrogen to make some low temp ice cubes or the other thing is to add the liq N2 to the solvent cooling bath so there is always liquid and frozen. Ether gives about -100oC when cooled with liquid N2.

The plastics that are OK at very low temps are usually based on polyethylene.

mick

added a bit

[Edited on 7-3-2005 by mick]

sparkgap - 8-3-2005 at 06:16

Something interesting:

Ozone melts @ -192 °C and boils @ -111.9 °C.

Nitrogen is a liquid at temperatures below -195 °C.

Getting the same ideas? :D

sparky (^_^)

New experiments with liquid Nitrogen

The_Fecalator - 15-3-2005 at 15:52

Today I thought about some interesting - more or less inventive - experiments to try with liquid Nitrogen.
Here are some ideas:
- I'd try to make a "snowball" out of solid Butane. With proper security precautions assumed, one could try to light the snowball and throw it against a fire resistant concrete wall or the floor. Then, the ball should either blow up in a nice fireball or the chunks will simply burn on the ground.
I'm serious about this experiment and I am well aware of the dangers involved. The question is: has anyone ever tried such an experiment or am I the only one foolish enough to attempt this one ?
- Another idea is to SAFELY explode a nitrogen bottle-bomb: A 1,5 litre Coke bottle (plastic, naturally) would FIRST be cooled down in liq. Nitrogen, THEN filled with some Nitrogen. After capping the bottle, it would instantly be dropped into a large barrel (about 100 litres in size) filled with about 10-20 litres HOT WATER. The water should provide for a rapid explosion of the bottle. I thought of this experiment as a way to show the destructive force of expanding Nitrogen without simply putting the bottle on a desk and wait for 20 minutes and the smithereens....
No need to mention any audience/spectator would be advised to stand well away from the barrel. I don't want people to be hit by shrapnel.
As I never did this stunt before, I can only guess it would create a nice little table tsunami....Nevermind, I'll definitely find out soon ;)
Edit by Chemoleo: Search next time before you post a new thread.

[Edited on 16-3-2005 by chemoleo]

Reverend Necroticus Rex - 16-3-2005 at 12:38

Sparky, liquid ozone is apparently very unstable and explosive, but then again, since when did THAT put anyone here off experimenting:D

I wonder, I have read of a further allotrope of oxygen, oxazone, O4, that can be fractionated from liquid ozone, and consisting of a few % of the volume of liquified ozone.

sparkgap - 21-3-2005 at 07:54

Knew someone just had to say that... ;)

That's why I suggested it in the first place!!!

Oxazone? I wonder how it looks like (Lewis structure, at least)? For sure, it's not a ring of four oxygens, or it would be incredibly unstable. Dioxetane (both isomers) is bad enough already.

sparky (^_^)

Fun with liquid nitrogen

franklyn - 24-6-2006 at 09:45

ifilm java script browser window diplays this streaming video

select your prefered player and connection speed to watch _

http://www.ifilm.com/player/?ifilmId=2744525&pg=default&...

Direct connection _

http://www.ifilm.com/player/?ifilmId=2744525&pg=default&...

Failure to play may mean you need Java runtime, get it here
uninstall Microsoft java first

http://java.com/en/download/index.jsp


well not quite instant iceskate rink but interesting. So what

else can you do with this stuff? I have seen people gargle

with it, yup insane I know. You can flash freeze a durable

steel part such as a padlock and shatter it with a blow of

a hammer. Useful for certain exotic chem synthesis.

Post other uses or ideas.

.

[Edited on 25-6-2006 by franklyn]

Nerro - 24-6-2006 at 10:01

You can freeze glass stirbars utterly and then drop them gently on the floor, they will shatter into 1000 pieces at least :D

you can freeze the toilets with it so flushing won't work anymore.

You can freeze someone else's plastic pen with it and see them crunch it when he grabs it.

You can freeze buthane with it while it's in the cillinder and then cut off the cillinder to collect the now waxlike butane to play with it.

the list goes on and on and on...


[Edited on Sat/Jun/2006 by Nerro]

Odyssèus - 24-6-2006 at 13:09

Theres superconductivity (with 'high-temperature' superconductors that work at liquid N temperatures) to play with. You can liquify oxygen and do things like pour it over magnets (Its magnetic) or over flammible stuff and incenerate/explode it.

You can liquify/solidify gasses that you wouldnt be able to at dry ice temperatures.

neutrino - 25-6-2006 at 08:08

I can't get the video to play. Can someone possibly rip it and upload it here?

franklyn - 26-6-2006 at 10:01

Quote:
Originally posted by neutrino
Overclocking isn’t necessarily cooling the processor. Rather, it’s modifying the processor’s instructions
in some way to run faster. This generates heat which tends to fry the chip, which is why you need a good
cooling system. I have heard of making chips run faster by cooling

August 2005
A Japanese overclocker has managed to overclock Intel Pentium 4
670 microprocessor to 7.132GHz and even run certain benchmarks on
the system that was cooled down by liquid nitrogen.
According to the posted statement, the system managed to calculate
π (pi) number to 1 million decimal places in 18.516 seconds, which
is currently the world’s record.

In order to accomplish the extreme overclocking Japanese
enthusiast Memesana, who published his results at XtremeSystems
web-site, used ASUS P5WD2 Premium mainboard based on Intel’s i955X
core-logic, Corsair PC2-5400UL 512MB memory modules as well as
Intel Pentium 4 670 processor with stock speed of 3.80GHz. The
processor system bus was overclocked to 1520MHz; processor’s
voltage was pumped up to 1.70V, significantly higher than default
setting; memory latency settings were CL4-3-3-4 memory voltage was
set to 2.3V.

See Picture -> http://img14.imagevenue.com/img.php?loc=loc265&image=288...

How To -> http://www.tomshardware.com/2003/12/30/5_ghz_project/index.h...
Quote:
Originally posted by neutrino
you get a nice, smooth ice cream because a.the nitrogen vaporizes
very quickly, preventing big crystals from growing

An icecream vender at a retail Mall sold scoops of ice cream pellets
that were made by dripping the batter as droplets into liquid nitrogen.
Flash frozen like this it becomes a material termed a glass without
crystal structure. Because glass is a poor conductor of heat and a
phase change from crytal state is not possible, these pellets resisted
melting remaining solid and cold for far longer than ordinary icecream.


Removing chewing gum or even solidified epoxy resin that has been worked
into a carpet is possible once frozen like glass. Wet with some naptha
tap with a hammer and brush.

.

[Edited on 26-6-2006 by franklyn]

Odyssèus - 26-6-2006 at 11:29

That reminds me... I recently watched a show on metals (Modern Marvels) where part of it was on metalic glass. I think they use liquid N to cool the metal very quickly and preventing crystals from forming, which makes it much stronger.

http://en.wikipedia.org/wiki/Metallic_Glass
Quote:

An icecream vender at a retail Mall sold scoops of ice cream pellets that were made by dripping the batter as droplets into liquid nitrogen.


I think the company your talking about is Dippin' Dots?

[Edited on 26-6-2006 by Odyssèus]

franklyn - 1-7-2006 at 17:55

Resources _

http://www.justnitrogen.com

dejitaru - 4-7-2006 at 01:22

Where do you get the nitrogen?

atarax - 6-7-2006 at 20:08

Try putting a big marshmallow in it for a few seconds. The outside gets crunchy.

franklyn - 13-8-2010 at 11:07

Liquid N2 in a swimming pool
These links from youtube are better than the others I had above
http://www.youtube.com/watch?v=XCtdW_BDuVI
http://www.youtube.com/watch?v=w2mj-Sq2oeo

.

peach - 14-8-2010 at 00:22

I like the butane snowball idea. Obviously, just be very careful with that. If you made a tiny mold from a bit of pipe or what not, you could freeze it into pellets and then blow pipe them onto a hard surface with a fire under it.

An old physics lab demonstrate is to dunk a filled balloon in it. It'll shrivel up to nothing, then re-expand when taken out.

If you're trying to make you're own ice cream don't fill a blender with it and then turn it on, as they do in this video

Here's NurdRage doing some things with liquid nitrogen;

Freezing ice
Breaking a heart, a whole body actually takes around 18h to reach cryogenic temperatures
Lowering the resistance of coils, if you dunk an LED in there, it's output should massively ramp up, as it will for a laser diode
Freezing acetone
Dunking his hand in it
Same again, but with some slow motion footage of the gas shroud


[Edited on 14-8-2010 by peach]

Formatik - 14-8-2010 at 01:31

I've frozen an iron pipe (maybe around 4cm in diameter) female attachment in liquid nitrogen. After a few moments, the metal became very brittle and simple blows from a hammer could break it up into pieces (at regular temperatures, these would just cause indentations). A small piece of aluminium foil rolled up into a ball and let sit in the nitrogen, then taken out after a few moments, only caused the foil piece to get flattened when hit with the hammer.

minor threadhijack: buying liquid nitrogen?

jgourlay - 14-8-2010 at 05:30

Gents, I have some experiments I'd like to try with liquid nitrogen. However, before trying to buy any, I'd like your advice on some points primarily surrounding how to purchase. My main concern is that anyone selling it, isn't going to sell to anyone who doesn't understand what they're doing.

I know I need a dewar. Beyond that, what is a source you all would suggest (preferably online) for getting training/education on all the safety issues relating to handling and transport?

Also, any suggestions about the best places/methods of approaching vendors about purchasing dewar quantities? I live in a large city that has Mathieson Trigas, Air Liquide, and other gas vendors. What I don't know is if you can walk into the plant, or do they distribute through middle-men, etc.

What do you suggest?

The WiZard is In - 14-8-2010 at 07:08

Quote: Originally posted by chemoleo  
I am in a somewhat lucky position, having access to liquid N2 anytime.

Can anyone think of interesting experiments to do with it?



Some use it in cooking.

Blumenthal-Style Chef Blows Off His while experimenting with a
Heston Blumenthal-style cooking technique.
10:44am UK, Tuesday July 14, 2009
A German chef has blown off his hands while experimenting with a
Heston Blumenthal-style cooking technique.


Liquid nitrogen used by some chefs as an instant cooler for food
The man, identified only as Martin E, was working on a recipe
involving liquid nitrogen when there was "a huge explosion",
according to the Berliner Morgenpost.


One of the 24-year-old's hands was instantly torn off by the force
of the blast, while the other was later amputated in hospital.

The explosion happened at his girlfriend's mother's house in
Stahnsdorf, near Berlin, where both women escaped without
injury.

The chef, a follower of "molecular gastronomy", had disappeared
into the bathroom with a bottle of liquid nitrogen.

He reportedly said afterwards he had been trying to fill a gas
lighter but his 16-year-old girlfriend said he was attempting to empty the bottle.

The young woman called the emergency services, who decided to
airlift the chef to hospital in a helicopter.

Scientific chef Blumenthal

Liquid nitrogen is pure nitrogen at a very low temperature, which

must be stored in special containers.
Its low boiling point, at -196C, means it can cause frostbite in
humans upon contact while it can also generate an explosion if the
liquid is vaporised into gas too quickly.

Cooking with liquid nitrogen was made famous by Blumenthal, the
celebrity chef known for his scientific approach in the kitchen.

Diners at his restaurant, The Fat Duck in Bray, Berkshire, are
treated to a green tea and lime mousse poached at their table in
the substance.

Blumenthal also used liquid nitrogen to attempt to break the world
record for making ice cream by using it as a coolant.

----
There was some discussion of this when it was first published, so
via. Google.com/news I pulled up the German newspaper accounts
and ran them through Yahoo Babble Fish.

He had taken some LN2 home in a container whose name I cannot
recall that was never/ever intended to be pressurized. The explosion occurred in his bathroom therefor I would posit he was
running it under hot water in an attempt to open it.....!

Noted in passing.

Harold McGee
On Food and Cooking : The Science and Lore of the Kitchen.
Simon and Schuster
1984
684 pages.

peach - 14-8-2010 at 13:10

Quote: Originally posted by Formatik  
I've frozen an iron pipe (maybe around 4cm in diameter) female attachment in liquid nitrogen.


Now that's an interesting one!

Perhaps due to the ductility of aluminium? Iron tends to be full of carbon trying to crystalise, as well as sulphur. Both are added to improve wear resistance and ?youngs modulus?, but both begin killing the ductility / elasticity. In the extreme of some cast irons, they'll (as you likely know) snap as if they're made of glass when hit sharply. Tool stools, high in carbon, have a tendency to do it (shattering machine tools etc).

I have seen a fair bit of what is likely quakery around LN2. When you combine something as mystical looking and extreme property bearing with the world of high end, very high price audio equipment, opinions that routinely deny statistical testing by their own claimants and thermionic valves, you get LN2 treated thermionic valves, "for that super cool sound!"

Quote: Originally posted by jgourlay  

What do you suggest?


In the UK, the liquid air people won't tap some off for you if you turn up. My local yards, which are big and packed full of cylinders (even odd ones) don't store the dewars. They're specially ordered and delivered. Indeed, you don't take your dewar back, they drive round with a truck that can dispense cryogens and pump it off with something that looks and acts exactly like a very cold petrol pump. Of coarse, there are special fees for that privilege.

In the US, I suspect you'll have more luck getting it on tap.

With regards to storing it, a thermos will work. The only really important thing to remember is that you need a little hole drilled in the lid. If you screw the lid on minus this hole, the thermos will explode as you drive home; which won't be fun at all, particularly if it's an all metal one. I would quite adamantly say that if you're planning to pick it up soon, and didn't realize that, you should certainly not pick it up soon.

Obviously, fix it in place so it won't topple as well. Not a big problem if it does, but you're LN2 will empty out all over the floor and rapidly disappear.

Having some genuine, significant sounding reason when you ask for it is probably a good idea as well.

E.g. "I want to do cool shit with it" <---- reworded to something equally basic, will make them assume you're going to hurt yourself or someone, resulting in them potentially getting a law suit filed letter, for the sake of making $1 on it.

franklyn - 14-8-2010 at 20:57

N2 Safety and Practice
http://www.chem.purdue.edu/chemsafety/Chem/ln2.htm

Make your own
http://www.instructables.com/community/Make-your-own-liquid-...
http://hackaday.com/2010/06/10/making-liquid-nitrogen-at-hom...

Commercial liquifaction equipment
http://www.elan2.com
http://www.elan2.com/product_elan2office.asp
http://www.elan2.com/product_elan2office_operation.asp
http://www.elan2.com/media/pdf/elan2TechBrief.pdf

The short arm of the law:
A liquid nitrogen dewar fill station may deny you buying it ,
but you can buy human fat in it, no questions asked.
http://www.reuters.com/article/idUSTRE5AJ2YB20091120

______________

Fun with Dry Ice
http://books.google.com/books?id=T-IDAAAAMBAJ&pg=PA925&a...