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Super cold LN2 replacement experiment – create an ultra-cold liquid nitrogen replacement using alcohol and dry ice.

Pouring liquid nitrogen into a plastic container

Ultra Cold LN2 Replacement that will instantly freeze anything!

NOTE: THIS EXPERIMENT IS HIGHLY HAZARDOUS AND CAN RESULT IN INJURY OR DEATH. IT IS NOT INTENDED TO BE CONDUCTED BY CHILDREN, BUT RATHER, IT SHOULD BE CONDUCTED BY SCIENCE TEACHERS ONLY!

Liquid nitrogen, represented by the equation LN2, is often used in higher level science experiments. In this experiment, we’ll create a liquid with the same “ultra cold” properties found in liquid nitrogen.

You’ll need two plastic bottles, one slightly smaller than the other.

  1. Cut the tops off of the two plastic bottles. Cut a few inches down so all the curved neck of the bottle is removed.
  2. In the smaller bottle poke a bunch of holes in the sides and bottom of the bottle.
  3. Now place the smaller bottle inside of the larger one. There should be about a finger’s width of space in between them.
  4. Pour the dry ice pellets into the space between the bottles. Keep the smaller bottle centered evenly so there is an equal number of pellets on all sides.
  5. Pour the alcohol into the space between the bottles making sure it runs over the dry ice (so it gets cooled). Note the fog that is produced.
  6. Now pour about 3 inches of alcohol into the center bottle. The alcohol in the center bottle will thicken (if you don’t use 99% alcohol it will really thicken). Bingo!  You have some ultra cold liquid!

Note: the alcohol will be extremely cold – if it comes into contact with your skin or any other part of your body, it will cause instant and EXTREME frostbite which will be very painful and dangerous!

Ultra-cold liquid nitrogen replacement experiment

liquid nitrogen pouring

LN2, or liquid nitrogen, is a pure form of nitrogen produced on an industrial scale by fractionally distilling liquid air. It has a boiling point of 77 K (-196 °C/-321 °F) at atmospheric pressure and is considered a cryogenic fluid due to its ability to cause rapid frostbite on contact with living tissue. Liquid nitrogen can be stored and transported when it is properly insulated from ambient heat, such as in a vacuum flask, where its very low temperature is held constant by slow boiling, resulting in the evolution of nitrogen gas.

Liquid nitrogen can be converted to a solid by placing it in a vacuum chamber that is pumped by a rotary vacuum pump. The freezing point of liquid nitrogen is 63 K (-210 °C/-346 °F).

While liquid nitrogen is often used as a coolant, its efficiency is reduced by the Leidenfrost effect, which causes it to boil immediately upon contact with a warmer object, creating an insulating layer of nitrogen gas around the object. To achieve more rapid cooling, an object can be plunged into a slush of liquid and solid nitrogen instead of just liquid nitrogen.

Liquid nitrogen is a compact and readily transported nitrogen gas source without pressurization. Further, its ability to maintain temperatures far below the freezing point of water makes it extremely useful in a wide range of applications, primarily as an open-cycle refrigerant, including:

  1. in cryogenics
  2. as a source of very dry nitrogen gas
  3. the immersion freezing and transportation of food products
  4. the cryopreservation of blood, reproductive cells (sperm and egg), and other biological samples and materials
  5. as a coolant for overclocking a central processing unit, a graphics processing unit, or another type of computer hardware
  6. as a method of freezing water pipes in order to work on them in situations where a valve is not available to block water flow to the work area.
  7. in cryotherapy for removing unsightly or potentially malignant skin lesions such as warts and actinic keratosis.
  8. in the process of promession, a way to dispose of the dead.
  9. cooling a high-temperature superconductor to a temperature sufficient to achieve superconductivity.
  10. the cryonic preservation of humans and pets in the hope of future reanimation.

The dangers of liquid nitrogen

iced nitrogen valves

Since liquid nitrogen’s liquid-to-gas expansion ratio is 1:694, a tremendous amount of force can be generated when liquid nitrogen boils off for whatever reason. In a well-known accident in 2006 at Texas A&M University, the pressure-relief devices of a tank of liquid nitrogen were sealed with brass plugs. As a result, the tank failed catastrophically and exploded. The force of the explosion was sufficient to propel the tank through the floor/ceiling immediately above it.

Nitrogen is odorless, colorless, and tasteless and may produce asphyxia without any sensation or prior warning. Due to its extremely low temperature, careless handling of liquid nitrogen may result in cold burns. It should be also borne in mind, that as liquid nitrogen evaporates it will reduce the oxygen concentration in the air and might act as an asphyxiate, especially in confined spaces. Lab worker James Graham famously died from asphyxiation after liquid nitrogen spilled in his laboratory in 1999.

More about using promession for the disposal of human bodies

One of the uses of liquid nitrogen is promession, an idea of how to dispose of human remains. Promession involves five steps:

  1. The body is placed into the chamber.
  2. Liquid nitrogen at −196 °C crystallizes the body
  3. The body is vibrated causing it to disintegrate into tiny particles
  4. Particles are freeze dried in a drying chamber, leaving approximately 30% of the original weight
  5. Any metals (e.g., tooth amalgam, artificial hips, etc.) are removed, either by magnetism or by sieving.

The dry powder is placed in a biodegradable casket which is interred in the top layers of soil, where aerobic bacteria decompose the remains into humus in as little as 6–12 months.

Ultra-cold liquid nitrogen replacement experiment supplies

Supplies: Plastic bottle, Alcohol (Pure or 99%), Dry ice

Image Credits

In-Article Image Credits

Iced nitrogen valves via Wikimedia Commons with usage type - Creative Commons License. July 2016
Liquid nitrogen pouring via Wikimedia Commons by Robin Muller with usage type - Creative Commons License. July 29, 2011
Pouring liquid nitrogen into a plastic container via Wikimedia Commons by Cory Doctorow with usage type - Creative Commons License. February 24, 2008

Featured Image Credit

Pouring liquid nitrogen into a plastic container via Wikimedia Commons by Cory Doctorow with usage type - Creative Commons License. February 24, 2008

 

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