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Liquifying Oxygen
Introduction
Oxygen makes up around 20% of the air around us. With the help of liquid nitrogen, we can easily distill it from the air and use fire to prove that it is indeed pure, concentrated oxygen
Description of the Experiment
For this experiment, we use an ordinary can (a cola can for example), which is mounted on a stand at an angle. For convenience when pouring liquid nitrogen, the top can be cut cut open. Under the can an erlenmeyer flask is suspended in a container filled with liquid nitrogen, to keep the flask cool.
The can is also filled with liquid nitrogen, which cools down the can and allows oxygen to condense on the can, and drip into the erlenmeyer.
The erlenmeyer, now containing liquid oxygen, is taken out of the container and matches are dropped in. The first few matches don't have to be lit, they will just serve as fuel. Eventually the matches are lit, resulting in an intense fire. While the oxygen is burning, more matches can be added to make the flame last up to 30 seconds.
Standard liquid nitrogen safety applies
Wear safety goggles: The flame can regularily launch hot/burning pieces of matches
Try not to look into the flame for too long. The flame is very hot and can give you temporary blind spots in your vision
Equipment and materials
References