The chapter on the properties of liquid oxygen thus ties in with this chapter closely. Various materials are immersed in liquid nitrogen to demonstrate the effects of low temperature on their physical properties. Liquid air is made and distilled to show that it contains oxygen and nitrogen. Liquid oxygen is made and its colour, magnetism and ability to support combustion are shown. Solid carbon dioxide is made.
Liquid nitrogen is boiled and the gas used to inflate a balloon and shown the volume increase.
Apparatus One vacuum flask - about 1.5dm is suitable. Ordinary household flasks appear to be suitable. It is helpful if more than one flask is available. Expanded polystyrene box such as those in which Winchester bottles are sometimes supplied. About 60 cm of copper tube as used for small-bore central heating systems.