how to make liquid nitrogen?

Question

ok well my sci teacher said that she made a liquid that is almost like liquid nitrogen it is not as cold she said to put dry ice in alcohol. I want to kow if that works and is there any other way to make it

Answer 1

One way to make liquid nitrogen is to use a compressor to compress, cool,
and then expand air many times until it has been cooled to about 77Kelvin,
where it will liquify (of course you will get oxygen, carbon dioxide and
water at various stages of the process as well). It is usually stored in
a Dewar -- essentially a thermos jug -- with a loose fitting cap (to allow
pressure to escape as the nitrogen evaporates rather than building up
pressure and becoming a bomb -- this is IMPORTANT!!). With appropriate
precautions (shield, goggles & gloves) it can be used safely in the
classroom though the students (or the instructor for that matter) should
not be allowed to play with it.
It can be obtained from Air Products

Answer 2

Your teacher put "dry ice" [CO2(s)], which sublimes at -78C, into alcohol. That means that the alcohol liquid reached a temperature of (theoretically) -78C. Liquid nitrogen boils at -196C. What is the "it" that you want to make? Companies everywhere in the U.S. and around the world make tons of liquid nitrogen every day. What they do is to compress and chill air until the air liquefies. Then they distil the liquid air. Nitrogen comes off first, leaving oxygen behind. Neon, argon, krypton, and xenon don't come into this.

So, what your teacher did was to put dry ice into alcohol. That meant that the temperature of the liquid could not get below -78C. But in theory, it meant that the temperature could never rise above -78C. This is because CO2 would change from solid to gas (sublimation) and keep the temperature low. In my experience, heat always flows into the vessel from the room, and the temperature of the alcohol liquid is always a "little" higher than -78C.

Answer 3

Liquid nitrogen boils at -192 deg C under one atmosphere pressure.

Dry ice (solid Carbon dioxide actually) sublimes at and maintains its temperature at -78 deg C under one atmosphere pressure. There is NO WAY you can make liquid nitrogen from a slush bath of alcohol and dry ice. I find it odd that your science teacher would suggest that you can make liquid nitrogen this way. Are you sure you heard her properly?

To liquify any material that is gas at atomospheric pressure and room temperature you have to cool it below its boiling point and / or increase pressure. Usually liquification of gasses is done by adding pressure and reducing temperature.

Answer 4

I've never heard of that but honestly I wouldn't even try. It sound pretty dangerous