Introduction

When liquid oxygen is poured between the poles of a magnet, some of the liquid is held in the gap until the liquid evaporates. The characteristic blue colour of liquid oxygen may also be displayed, as well as the effect of a high concentration of oxygen on the rate of combustion.

Method

Effect of a Magnet on the Flow of Liquid Oxygen

Liquid nitrogen is made to flow past a strong magnet. There is no effect on the flow by the magnet.

Liquid oxygen is made to flow past a strong magnet. Liquid oxygen is attracted to the magnet and can be clearly seen to flow towards it.

Comparing the Colour of Liquid Nitrogen and Liquid Oxygen

Beakers of liquid nitrogen and liquid oxygen are observed. Liquid nitrogen is colourless while liquid oxygen is blue in colour.

Effect of Liquid Oxygen on Combustion Rates

Combustibles are dipped into liquid oxygen, then a burning splint is used to light them. The same combustibles can be burned in air to compare the combustion rates. Materials burned were: cotton wool, iron wool and crisps.