Main Difference – Liquid Nitrogen vs Nitrogen gas
Nitrogen is a chemical element having the symbol N. It is one of the essential elements for life. Nitrogen can form many different organic and inorganic compounds. Nitrogen makes up roughly 78% of the earth’s atmosphere. Nitrogen gas can be liquefied. Nitrogen gas and liquid nitrogen have many applications. Both these nitrogen forms are composed of N2 molecules. The main difference between nitrogen gas and liquid nitrogen is that liquid nitrogen is man-made while nitrogen gas naturally occurs in the atmosphere.
Key Areas Covered
1. What is Liquid Nitrogen
– Definition, Properties, Uses
2. What is Nitrogen Gas
– Definition, Properties, Uses
3. What are the Similarities Between Liquid Nitrogen and Nitrogen Gas
– Outline of Common Features
4. What is the Difference Between Liquid Nitrogen and Nitrogen Gas
– Comparison of Key Differences
Key Terms: Cryogenic, Fractional Distillation, Liquid Nitrogen, Nitrogen, Nitrogen Gas, Phase of Matter
What is Liquid Nitrogen
Liquid nitrogen is nitrogen that is in the liquid phase. Nitrogen exists in this liquid form at extremely low temperatures. Liquid nitrogen is composed of N2 molecules. This liquid form is denoted as LN2. At normal pressure, liquid nitrogen boils at −195.8°C.
This liquefied form is produced industrially via fractional distillation of liquid air. Liquid nitrogen in non-toxic, colorless, odorless and inert. It is not a flammable liquid. It is a cryogenic liquid. That means it can cause a rapid freezing when contacted with living tissue. Therefore, care should be taken when handling liquid nitrogen, preventing inhalation and direct contact with skin.
Figure 2: Liquid Nitrogen
Liquid nitrogen boils very quickly. Hence, the transition of liquid nitrogen into gaseous form causes the build-up of a high pressure due to the expansion of volume. Therefore, sealed containers are not used to store liquid nitrogen.
The applications of liquid nitrogen are chosen based on the low temperature and low reactivity. The major applications include freezing and transport of food, cryopreservation of biological samples, cryotherapy, as a source of extremely dry nitrogen gas, etc.
What is Nitrogen Gas
Nitrogen gas (N2) is a colorless, odorless gas which makes up roughly 78% of the earth’s atmosphere. It is an inert gas. The molar mass of nitrogen gas is 28.014 g/mol. Nitrogen gas is slightly lighter than normal air.
Nitrogen gas can be converted into liquid nitrogen at temperatures below the boiling point of nitrogen. Nitrogen can solidify at temperatures lower than the melting point. N2 molecules are covalently bonded to each other via a triple bond. This triple bond causes the chemical inertness of nitrogen gas.
Figure 2: A Tyre Filled with Nitrogen Gas
Nitrogen gas has industrial applications, especially in the food industry. Nitrogen gas is used to fill the environment inside a food package. This is called a modified atmosphere. It helps to preserve the freshness of food. Apart from that, it is used in the manufacture of stainless steel.
Similarities Between Liquid Nitrogen and Nitrogen Gas
- Both are composed of N2
- Both are colorless and odorless substances
- The molar mass of both substances is 28.014 g/mol.
Difference Between Liquid Nitrogen and Nitrogen Gas
Definition
Liquid Nitrogen: Liquid nitrogen is nitrogen that is in liquid phase.
Nitrogen Gas: Nitrogen gas (N2) is a colorless, odorless gas which makes up roughly 78% of the earth’s atmosphere.
Occurrence
Liquid Nitrogen: Liquid nitrogen is man-made.
Nitrogen Gas: Nitrogen gas naturally occurs in the atmosphere.
Phase of Matter
Liquid Nitrogen: Liquid nitrogen is in the liquid phase.
Nitrogen Gas: Nitrogen gas is in the gaseous phase.
Uses
Liquid Nitrogen: Uses of liquid nitrogen include freezing and transport of food, cryopreservation of biological samples, cryotherapy, as a source of extremely dry nitrogen gas, etc.
Nitrogen Gas: Nitrogen gas is used to fill the environment inside a food package.
Conclusion
Liquid nitrogen is the liquid form of nitrogen gas. It is very useful as a freezing agent. Nitrogen gas is used to fill automobile tires and also used in food industry as a packaging environment. The main difference between nitrogen gas and liquid nitrogen is that nitrogen gas is in the gaseous phase whereas liquid nitrogen is in the liquid phase.
References:
1. Helmenstine, Anne Marie. “Liquid Nitrogen Facts.” ThoughtCo, Jun. 20, 2017, Available here.
2. Helmenstine, Anne Marie. “Everything You Need to Know About Liquid Nitrogen.” ThoughtCo, Available here.
3. “Nitrogen.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
Image Courtesy:
1. “Liquidnitrogen” By Cory Doctorow aka gruntzoki on Flickr – (CC BY-SA 2.0) via Commons Wikimedia
2. “Wheelbarrow tyre” By TheOminousDonut – Own work (CC BY 4.0) via Commons Wikimedia
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