# What is Liquid nitrogen: Definition and 45 Discussions

Liquid nitrogen—LN2—is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about −195.8 °C (−320 °F; 77 K). It is produced industrially by fractional distillation of liquid air. It is a colorless, low viscosity liquid that is widely used as a coolant.

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1. ### COMSOL: Simulation of liquid nitrogen cooling (Help please)

The InSb sample (parameters 10x10x0.5 mm) is glued with silver glue to a cooled copper table. Liquid nitrogen passes through the table. While the model is at a temperature of 300 K and at a normal pressure of 1 bar. The sample is affected by a beam of electrons, which causes the surface to heat...
2. ### Time to evaporate LN2 from a container

Hello, Could someone please help me understand how to approximate how long it will take for liquid nitrogen in a room temperature container to completely evaporate. Here's the scenario: I have a metal container (41x13x15") filled with 5.5" of liquid nitrogen (just released from a Dewar ~ 320F)...
3. ### Heat capacity vs Thermal conductivity in a LN2 bath

I worked on a lab experiment that was meant to measure heat capacity but left me with some other questions. The students measured the mass of a cup of liquid nitrogen as it boiled off, recording mass vs time. Then they drop a solid object into the bath, one experiment with a small bit iron...
4. ### How to calculate change in pressure from LN2 phase change

I am trying to calculate the increase in pressure caused by liquid nitrogen when it changes from liquid to vapor within a closed, constant volume at atmospheric pressure. How can this be done? Do I need to include the heat of vaporization?
5. D

### Is the mass of Liquid N2 and its rate of mass loss related?

Homework Statement So I'm doing an experiment at uni which I have to find out the specific heat capacity of given small solid cylinder. We are given an insulated canister(a dewar flask) standing on a scale where we have to pour Liquid Nitrogen(hereafter will be referred as LN2) in. A cork with...
6. ### Need Help Solving Set of Coupled ODEs

Homework Statement Liquid nitrogen is in a dewar connected to a vacuum pump. Initial pressure in a dewar is 1atm and saturated with gaseous nitrogen. If the vacuum pump started, it removes gas in it and the pressure in a dewar will be reduced under the saturation pressure of the liquid...
7. ### Heat convection in liquid nitrogen

Hello, I am trying to achieve a range of temperature (below 0 degC) by heating up liquid nitrogen (77K) with an electric heater (100W) inserted into a copper block. How do I calculate the time taken (t) for the nitrogen vapour to reach temperature T (say 100K). The liquid nitrogen is poured into...
8. ### Heat energy and liquid nitrogen boil-off rate

Homework Statement Kindly refer to part (c). The woking should be power/0.35 (what I think according to the graph). But the answer is power (that is the answer of part b) divided by 0.02 Homework Equations I have used the ratio method simply The Attempt at a Solution According to part (b)...
9. ### Where can you buy a cheap liquid nitrogen dewar?

I want to find a Dewar or vacuum flask for liquid nitrogen under \$50. Does anyone have any recommendations where to buy one?
10. ### Maintaining -320°F Liquid Nitrogen for Injection Molding

I have a plastic injection mold, the part I am running has hot spots in the part when it is being shot in the mold. Would like to try to incorporate a closed loop plumbing system to carry liquid nitrogen past the back side of the cavity in hopes to pull the trapped heat from the hot spot area...
11. ### What is the Best Way to Install a Cryogenic Finger in a High Vacuum Chamber?

Hi, I have a high vacuum chamber, where I would like to feed a cryogenic finger through. The finger is to be mounted on top of the chamber (flange is parallel to floor), and the flange is a 4.5" Conflat type. I have a few options, and want to know how best to proceed. 1) I have an existing...
12. ### Ground-based Laser + Liquid Nitrogen Rocket Engine?

No idea why this popped into my head on the drive home tonight, but here we go: Would it be possible to build a rocket filled with either liquid Nitrogen, or some other super-cooled substance, then use a battery of high-energy, ground-based laser beams pointed at the super-cooled propellant to...
13. ### How to Create Liquid Nitrogen Using Dry Ice and Alcohol

Hi Everyone liquid nitrogen is very useful . i want to know how to make liquid nitrogen? i won't make a one. but i only want to know how to make it .
14. ### Practical question liquid nitrogen stump removal

Ok so I need to get a 3foot stump out of concrete without damaging the concrete. It's at that terrible stage where it's to rotten to pull out and to solid to scoop out. My idea is to drill a hole and pour liquid nitrogen down the hole to make the wood brittle and then smash it with a pry bar...
15. ### What can be used to measure liquid nitrogen temperature?

Hi. I'm looking for a common electronic component that can be used to determine a temperature between room temperature and that of liquid nitrogen. -Multimetre probe failed, getting stuck at -135*C -Common NTC thermistors rapidly ascent past gigaohm range, even from 1Ω-5Ω initial values...
16. ### Liquid nitrogen generator, N2 gas generator

I thought some of you engineers would be interested in reading my web tutorials. I have written some extensive tutorials on the theory and building of a homemade N2 gas generator. It takes regular air, and using pressure swing adsorption, concentrates the N2 up to 99%. This is here. I then...
17. ### Green LED in liquid nitrogen turns yellow

Hi, While experimenting with various LED's in LN2, I noticed some strange behaviour from my green LED's. As expected all LED's (except the green one's) emitted light with a shorter wavelenth (for instance, my yellow led turned to red etc). However, my 2 (different manufacturer type LED)...
18. ### Liquid nitrogen transfer into nitrogen purged enclosure

I am trying to build a system to transfer liquid nitrogen (LN) into a roughly 6'x4'x2' sealed nitrogen gas-purged enclosure. The LN is in a pitcher-style dewar like this http://static.coleparmer.com/large_images/03773_51.jpg but with an open top, and the container I'd like to transfer it into...
19. ### Making Liquid Nitrogen at Home: Have You Tried It Yet?

A while ago I had asked if anyone ever made liquid nitrogen from scratch without using a prepackaged cooling device (cryocooler). Well, I've done it. I'm working on a web tutorial and better video footage. For those who wish to make suggestions on what you would like to see I am submitting...
20. ### Increase in Wavelength of an LED Immersed in Liquid Nitrogen

Hi, I've been working on an experiment where I dip LEDs into liquid nitrogen and note the color change. All online sources I've seen predict that the wavelength of the light emitted by the LED will decrease upon immersion. What I've been observing, however, is a sudden decrease in...
21. ### What Are the Electrical Resistance and Heat Capacity of Liquid Nitrogen?

I have two questions for you guys A) what is the electrical resistance per meter of Liquid Nitrogen and B) What is the heat specific heat capacity of Liquid N.
22. ### Medical Girl drinks liquid nitrogen, has stomach removed

An 18-year-old teenager has had to have her stomach removed in an emergency operation after drinking a cocktail containing liquid nitrogen. http://www.bbc.co.uk/news/uk-19878511 Question? How does she eat food without a stomach? Carry a bag?
23. ### Plastics to tolerate -300F for liquid nitrogen generation

Maybe someone here will have an idea where I can get some information. I am planning on making liquid nitrogen from air and will need to regenerate waste gas. This gas will be very cold (-300F) and will get transported through some tubing system. Is anyone aware of any plastic tubing material...
24. ### Making liquid nitrogen from air

Has anyone done this as a DIY project? I want to use a refrigerator compressor with counter-current coils.
25. ### What is the Entropy of Liquid Nitrogen at 77.244K and 1bar Pressure?

Hi All, I tried to find entropy of liquid nitrogen in various data books, using nitrogen's CAS number, MSDS, but I was able to get the entropy of nitrogen till only 100K, not below that. Does anyone know what's the entropy of liquid nitrogen or that where can I find it? Thanks!
26. ### Behavior of Liquid Nitrogen at 3000psi & 6000psi

hi all How would nitrogen behave at 3000psi? or 6000psi? assuming it starts at liquid form and at 1 atms pressure heated to 20 Celsius. thank you
27. ### Determining Capacity of Liquid Nitrogen Supply System

Im working on an exisiting Ntirogen supply system that's used to blanket boilers and pipelines etc. at a thermal power plant. I am trying to determine the capacity of the system. I have determined the size of the liquid ntrogen tank to be 8m^3 but I'm lost on how to determine the amount of gas...
28. ### How much liquid nitrogen is needed to maintain constant evaporation?

How much liquid nitrogen? Hi All, A liquid nitrogen evaporation question for you :) A large metal container is kept at constant temperature of 40 degrees Celsius. This container has a long 10inch diameter tube opening connected to its top. Through a second opening liquid nitrogen...
29. ### Thermodynamics question. In Dewar flask liquid nitrogen.

Homework Statement The problem is that we need to calculate, how much time it takes for nitrogen to evaporate. Given data: dewar flask is in a room, where is T= 293K temperature; In such flask m=0,2 kg of Hydrogen would evaporate in t= 3600s. Also there is given boiling point temperatures for...
30. ### Evaporation Rate of Liquid Nitrogen

Hello everyone! I am trying to design a magnetic testing apparatus that needs to remain at -196K for 20 minutes. There is not exactly a straight foreword equation to get a calculation for the evaporation rate of liquid nitrogen. The apparatus looks like this, and I have highlighted the area...
31. ### Liquid Nitrogen Injection Underground Last Defense

Only assuming that the worst will happen and that will include the complete breaches through the bottom of the sealed containment of all four reactors, wouldn't it be possible, first, and then prudent, second, to be ready to cool these molten masses with liquid nitrogen being injected...
32. ### Light source at liquid nitrogen temps

Can anyone recommend a white light source to be used in a cryostat down to 77 K? We are using it in temperature-dependent studies of PV devices. Currently we have an incandescent bulb which has shifted its spectrum towards red over time and we're looking for a replacement. It would be nice to...
33. ### Experimenting with Liquid Nitrogen: Who's Right?

I'm supposed to do a little demonstration to some middle school kids and one thing that's planned is sticking a balloon in liquid N2. The guy who showed us what they want (who doesn't appear to know anything about science) claimed that the liquid you see in the bottom of the balloon when you let...
34. ### Designing a Liquid Nitrogen Container for Efficient Coilgun Operation

I'm constructing a pulsed solenoidal accelerator (coilgun) and am looking to boost efficiency by supercooling the copper wire in the coil. I'm also getting a quote for a high-temperature superconductor film to use in place of the copper wire. In either case, I will need submerge the coil in...
35. ### Would it be possible to create a sterling engine out of liquid nitrogen and air?

Is the heat difference enough to cause a noticeable power output in some type of sterling engine? Liquid nitrogen is quite cheap (alternative fuel source?)
36. ### So, my question is, can the cold truly burn you?

Hi, I was wondering, what is a cold burn exactly? We were told that liquid nitrogen (or anything that cold for that matter) can cause cold burns when touched... How can something cold burn you? Or is it not burning you but is it merely named 'cold burn' even though it is simply freezing...
37. ### Strange Behaviour of Aluminium in Liquid Nitrogen

i was doing an experiment with liquid nitrogen, i had to put an aluminium body initially at room temperature inside a glass with the nitrogen at 77K, first it starts making a loud noise then a lower noise that is slowly increasing and finally near the equilibrium point the noise gets strangley...
38. ### How fast does liquid nitrogen expand

i would like to know how fast and how much liquid nitrogen (-200 degrees Celsius) expands when it is heated with gasses of about 3000 degrees Celsius
39. ### Exploring Heat Transfer: The Leidenfrost Effect and Walking on Hot Coals

I've always wondered how people are able to walk on hot coal without suffering from burns. Moreover, earlier, a teacher demonstrated to my class how if one spills liquid nitrogen on one's hand in open air that one does not suffer from frostbite, but only feels the cold temperature. I got...
40. ### Exploring the Wonders of Liquid Nitrogen

Liquid nitrogen! No, I don't have any, but I WANT SOME. I have no idea how to proceed. How much does it cost, flask included, and where can I get it? Do I have to use all of it right away, or can I store it for more than a few days? What kind of saftey should be taken into consideration besides...
41. ### Liquid Nitrogen vs. Liquid Helium

What do you think is better? Lets start a debate!
42. ### Liquid nitrogen temperature superconductors

Hi, I have started Plysics 20 by correspondence and I can't find the answer to this question: The reason that liquid nitrogen temperature superconductors are important is that liquid nitrogen costs less than liquid helium. New technologies to store liquid helium have been developed in the...
43. ### Unlocking the Mysteries of Liquid Nitrogen

So i have been doing thsi question for about a week now and it's about liquid nitrogen. Here it is. Liquid nitrogen is used in many low-temperature experiments. It is widely available, and cheaper than gasoline! How much heat must be removed from room temperature (20C) nitrogen gas to...
44. ### Cooling with Liquid Nitrogen & Melting Aluminum Cans: Energy Calculations

Problem 2. Liquid nitrogen, which has a boiling point of 77 K, is commonly used to cool substances to low temperatures. How much energy must be removed from 1.4 kg of gaseous nitrogen at 77 K for it to completely liquefy? Assume the latent heat of liquid nitrogen is 2.01 *10^5 J/kg Answer...
45. ### Finding Liquid Nitrogen for Experiments: Where to Order

My friend and I have a lot of ideas for liquid nitrogen experiments (and we will be safe! :)), but we have no idea where to order it from. If from an online source, try to be specific. If in reality, try to give a little input on the process. Thanks.