Liquid Nitrogen in Dewars containers, Copper funnel, tongs
Liquid Nitrogen, Dewars, and Balloon
Liquid Nitrogen, Dewars, and Balloon

 

Code Number: 4C30.80

Demo Title: Liquid Nitrogen - Making Liquid O2 & Liquid Argon

Condition: Excellent

Principle: Cryogenics

Area of Study: Thermodynamics

Equipment: 

Liquid Nitrogen, Copper funnel, Dewars, Test tubes with air inlets.

Procedure:

NOTE:  The equipment for this demonstration can be found on the 4A40.70 shelf.  This equipment is also used for the 4A40.70 and 5G30.20 demonstrations.

Pour liquid nitrogen in the small dewar to cool it to the proper temperature.  When the boiling ceases, pour all the liquid nitrogen from the dewar into the copper funnel.  Place the dewar under the point of the copper funnel to collect the liquid oxygen.  You should be able to collect 50 to 100 ml of liquid oxygen in a 20 minute time frame.

To make liquid Argon from the Argon gas cylinder you need to connect a small hose to the special test tube as shown.  Put a 12 or 14 inch balloon onto the top of the test tube.  Carefully open the gas cylinder and inflate the test tube/balloon apparatus with Argon until the balloon is good sized.  Pour some liquid nitrogen into a small dewar and insert the test tube/balloon system into the liquid nitrogen.  As the Argon condenses in the test tube, the balloon will shrink in size.  Re-inflate with Argon gas as necessary until the desired amount of liquid Argon is collected. 

References:

  • Thomas K. McCarthy, "Two Cryogenic Demonstrations", TPT, Vol. 29, # 9, Dec. 1991, p. 575.
4C30.80 - LIquid Nitrogen and Making Liquid Oxygen