Learn the basics about the properties of nitrogen as a part of the overall properties of matter topic.
Nitrogen makes up approximately 78% of the air around us.
In this lesson, we will learn about nitrogen, its properties, and its real-life applications.
Nitrogen is a colourless, odourless gas at standard ambient temperature and pressure.
It is extracted from air by liquefaction and fractional distillation.
These processes are explained in another lesson.
Atmospheric nitrogen is naturally fixed, or reacted to form a compound, into soils by lightning or certain types of bacteria.
Nitrogen is an essential element in the structure of proteins and DNA but plants cannot get it directly from air as the N-N triple bond is very strong, so it has to be “fixed” into soils.
This is a part of a much larger and important nitrogen cycle.
Nitrogen gas is used in the Haber process for the industrial manufacture of ammonia.
Ammonia is an important starting material in the production of nitric acid, fertilisers, pharmaceutical products, and explosives.
For certain chemical and industrial processes, an unreactive atmosphere may be required.
This means that the reaction conditions must be made to be oxygen-free.
This is because unwanted oxidation reactions may occur or oxygen may bind to certain substrates and prevent a reaction from occurring.
These reactions are conducted under either a nitrogen or argon atmosphere.
Nitrogen is cheaper than argon and more readily available and would therefore be the choice atmosphere for industrial chemists in such scenarios.
The next time you purchase a bag of chips or crisps, notice how the bag is rather puffy.
The gas inside the bag is actually nitrogen.
As much oxygen as possible is removed, so to prevent bacteria from growing, thereby increasing its shelf life.
In fact, nitrogen is very important in packaging of many food products, from fruits and vegetables, to processed foods such as your bag of chips or crisps.
Without it, spoilage will occur much quicker leading to increased waste production.
Gas chromatography is used to separate compounds based on their volatility.
This is done by flushing an inert or unreactive gas through a provided sample injected in a gas chromatograph.
This gas can be helium or nitrogen.
Nitrogen is the gas of choice for this technique because the supply of helium on Earth is dangerously low and as a consequence, its market value has significantly increased.
Liquid nitrogen also has many important real-life applications.
Nitrogen boils at -196ºC, so you can imagine how absolutely cold liquid nitrogen is.
Now you may wonder, what is the use of something that is so cold?
Some industrial reactions are highly exothermic, and liquid nitrogen is used to cool down such reactions.
Liquid nitrogen is also used to preserve many biological specimens, such as blood and tissue samples.
Therefore, it plays an important role in scientific research.
It is also used in the medical field to remove warts and certain other skin abnormalities.
The wart is frozen by applying liquid nitrogen, and it is then safely removed.
This is called cryotherapy, where “cryo” is used to denote very low temperature conditions.
Research studies conducted at very low temperatures are called cryogenics.