Liquid Nitrogen
Liquid Nitrogen is a clear, colorless liquid. It consists of molecular Nitrogen cooled down so that the molecules condense and what is normally a gas becomes a liquid. Because liquid Nitrogen boils at very low temperatures, it will boil rapidly at room temperature.
Fast Facts
- The same type of Nitrogen that is found in 80 percent of the atmosphere (N2) but in a liquid state
- Boiling point: -320.5°F (-195.8°C)
- Transported in special vacuum containers called Dewar flasks
- Expands to 694 times its size when turning from liquid to gas
- Can rapidly freeze small items like flowers, racquetballs and balloons within seconds
Uses For Liquid Nitrogen
Liquid Nitrogen is used in many applications. Because it is very cold, it is used as a coolant. It is also used to freeze off skin lesions such as warts. Due to its unique properties and the ability to rapidly freeze things, liquid Nitrogen is often used in classrooms to demonstrate the states of matter and gas laws.
Liquid Nitrogen Dangers and Safety Precautions
Although liquid Nitrogen is not toxic, it can be dangerous if treated improperly. Because it is very cold, cold burns are one potential danger. Another potential danger comes from the rapid expansion of liquid Nitrogen as it warms up. This expansion can cause explosive force if the nitrogen is not stored properly. Expanding Nitrogen can also displace the oxygen in a small, enclosed space, causing asphyxiation. Scientists recommend the following safety precautions when using liquid Nitrogen:
- Wear safety glasses, insulated gloves and other protective gear
- Use in a well-ventillated area
- Sore in a Dewar flask or other specially-designed vacuum container
- Avoid getting liquid nitrogen on skin
- Do not ingest liquid nitrogen
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