Nitrogen is the most prevalent chemical element in the Earth’s atmosphere and is integral to both plant growth and reproduction. As such, it is used in several practical uses.
At room temperature, nitrogen it is just an average looking clear gas. That said, it appears differently depending on its state. For example, most people have never seen nitrogen in its solid form yet as a solid, it is a beautiful substance. Every state, whether liquid, gas or solid, serves many purposes.
Liquid nitrogen is nitrogen that gets cold enough to exist in liquid form. In a liquid state, it exists at an extremely low temperature. It has several practical applications in today’s society, including several cryogenic and cooling uses. It is the liquified form of nitrogen and is made by fractional distillation of liquid air. It is made of two nitrogen atoms sharing covalent bonds.
Nitrogen is quite boring in appearance. It has no color or odor and it is nontoxic. It is also not flammable. Nitrogen gas is a little bit lighter than air when it gets to room temperature and it is a bit more soluble when in water. It was first made into a liquid on April 15, 1883.
How Cold is Liquid Nitrogen?
Nitrogen is a gas at room temperature but is transformed to a liquid when it is cooled to negative 320 degrees Fahrenheit. Once liquid, it can be transformed further if placed in a vacuum. By putting the liquid in a vacuum, you can create nitrogen glass.
In the form of liquid, Nitrogen is between the temperatures of -210 °C and -196 ° C. In Fahrenheit, that temperature translates to the range of -346 degrees to -320.44 degrees.
Once it reaches -210 °C, nitrogen freezes and transforms into a solid. When above -196°C, nitrogen boils and transforms into a gas.
The appearance of nitrogen varies depending on its current state. Liquid nitrogen looks the same as boiling water. Its solid form is very rarely seen, and most people have not seen and will likely never see solid nitrogen.
The storage for liquid nitrogen is fairly particular. It needs to be stored in specified insulated containers that have vents to help prevent any buildup of pressure. Depending on the container, liquid nitrogen can be stored for a wide range of time, starting at just a few hours and going all the way up to several weeks.
While not toxic, liquid nitrogen can still cause some hazards, some of which can prove severe if users are not careful.
To start, when liquid changes into gas, the nitrogen concentration in the area immediately increases. As such, the concentration of other gases simultaneously goes down, particularly lower to the ground and near the floor. This is because cold gases are heavier than warm gases and given their heavier weight, they sink.
Another risk associated with liquid nitrogen relates to its temperature. It is very cold which can cause severe issues for living tissue. The liquid evaporates quickly so a small amount really doesn’t cause any trouble. However, a large amount can cause major problems, including frostbite.
Frostbite can be prevented if precautions are taken. First, wearing proper safety gear is a must. This means covering up any exposed skin to limit exposure and contact. This covering up is similar to what anyone in a cold climate would do when stepping outside.
This can help prevent any inhalation of the cold gas and can also help prevent direct contact. Exposure can be almost fully prevented just by covering and insulating the skin.
Breathing issues can be created through the use of liquid nitrogen. One example of when liquid nitrogen can cause this kind of issue is when it is used to create a kind of fog for a pool party. This is a typical use of liquid nitrogen but can cause an issue. The significance of the issue depends on the amount of liquid nitrogen used.
If a smaller amount of liquid nitrogen is used, the pool temperature won’t be impacted. The excess nitrogen is just blown away and there is really no issue.
However, if a large amount of liquid nitrogen is used, the oxygen concentration on the surface of the pool can go down far enough that it can cause hypoxia or breathing issues for anyone in close proximity.
Another potential hazard is the pressure that vaporizing nitrogen puts on its immediate surroundings. This is because the liquid expands to 174.6 times its original volume in its transition to a gas state. The gas then expands another 3.7 times when and as it warms to the room temperature. The total volume increase is 645.3 times.
It expands a tremendous degree This means that liquid nitrogen should absolutely never be stored in a sealed container. If it is, the risk is that the container could burst. There are very particular ways to store liquid nitrogen, which take into account the expansion that takes place. These specified containers are the only safe way to store liquid nitrogen
Liquid nitrogen has several practical uses in today’s society. This is primarily due to its very cold temperature. Many consumers might best know liquid nitrogen from its growing use at popular restaurants. It is used in a specialized cooking technique that helps to instantly freeze food or drinks that then creates a cloud of vapor or fog when it is exposed to air.
There are also several very useful and practical uses for liquid nitrogen. It can be used for moving and freezing food products. It can also be used as a coolant for a variety of materials and items including vacuum pumps and superconductors.
It has cryotherapy uses as well, including removing abnormalities in the skin and can be used for cryopreservation for a number of biological samples, both human and animal.
Finally, liquid nitrogen is often used in science experiments. The most common of these is freezing flowers and then shattering them, making nitrogen ice cream and making nitrogen fog.
Also read: Where to Buy Liquid Nitrogen