Transcript of video
How is Nitrogen used?
“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. Nitrogen is extracted from air using liquefaction and fractional distillation.
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 obtain it from the air as the nitrogen nitrogen triple bond is very strong, so it has to be fixed into soils. This is the part of a much larger and important nitrogen cycle.
We will first discuss the uses of nitrogen as a gas. 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 happening. These reactions are conducted under 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 the packaging of many food products, from fruits and vegetables to processed foods such as your bag of chips. Without it spoilage will occur much quicker, leading to increased waste production. A method to separate compounds on their volatility is called gas chromatography. This is done 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 real-life applications. Nitrogen boils at minus 196 degrees Celsius, so you can imagine how absolutely cold nitrogen is. Now you many wonder, what is the use of something that is so cold. Some industrial reactions are highly exothermic and liquid nitrogen is used to coold down such reactions. Liquid nitrogen is also used to preserve many biological specimens such as blood and tissue samples. Therefore it plays and important role in scientific research. It is also used in the medical field to remove warts and 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 describe very low temperature conditions. Research studies conducted at very low temperatures is called cryogenics.”