Can a freezer contain liquid nitrogen for a long time?
If not could someone please explain what dewar containers are?
- 1 decade agoFavorite Answer
A freezer runs at around 0 degrees Celsius and the boiling point of liquid nitrogen is about -200 degrees Celsius, so even in the freezer liquid nitrogen is going to evaporate. A dewar is a metal (usually) container which is double walled and in between the two walls is a vacuum, since vacuums are the best possible insulator. This allows the liquid nitrogen to keep itself cold, and absorb as little heat from it's surroundings as possible. However even in a dewar the liquid nitrogen will evaporate so it needs to have a release or it will become highly pressurized. This is why dewars have either a release valve or a top which is not sealed.Source(s): Chemistry Major who uses Liquid N2 a lot.
- 1 decade ago
Depending on your quantity, say a liter, in a typical freezer in a typical container will not last all that long probably no longer than 12 hrs.
Dewars are just really expensive coolers that hold liquid nitrogen. they come in a wide variety of shapes, sizes and prices depending on your needs. Some very nice dewars are much like a cooler except there is a vacuum between the inside and outside of the dewar. Because there are very few molecules present in the vacuum region little heat is transferred to the surroundings which can keep liquid nitrogen cool for impressively long times.
- 1 decade ago
I am sure it has liquid nitrogen...