At high altitudes, water boils at a lower temperature, as anyone who cooks in the mountains knows.). Cryogenic liquids are liquefied gases that have a normal boiling point below -150o C (-238o F). [20], Vessels containing liquid nitrogen can condense oxygen from air. low entropy). Next time on Chemistry in its element, how chemists like Mendeleev got to grips with both the known and the unknown. An air compressor is used to compress filtered air to high pressure; the high-pressure gas is cooled back to ambient temperature, and allowed to expand to a low pressure. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. Questions and Answers. We welcome your feedback. Atoms of the same element with different numbers of neutrons. Crop yields can be greatly increased by adding chemical fertilisers to the soil, manufactured from ammonia. The efficiency of the Carnot engine is \(73.72\% \). Discuss your ranking in terms of microstates and macrostates. Annealing is a heat treatment that makes steel easier to work. 18, 2022, thoughtco.com/liquid-nitrogen-facts-608504. Thermometers measure temperature by using materials that expand or contract when heated or cooled. Liquid nitrogen can be held for several hours in a vacuum flask. It is used for storing sperm, eggs and other cells for medical research and reproductive technology. Tabulated values of nitrogen density at given temperature and pressure (SI and Imperial units) as well as density units conversion are given below the figures. The force of the explosion was sufficient to propel the tank through the ceiling immediately above it, shatter a reinforced concrete beam immediately below it, and blow the walls of the laboratory 0.10.2m off their foundations.[16]. When he presented the table to the world in 1869, it contained four prominent gaps. These applications will - due to browser restrictions - send data between your browser and our server. Solid nitrogen is the solid form of the element nitrogen. You do not have JavaScript enabled. Because its so cold, liquid nitrogen can liquefy oxygen from air. Oxygen can accumulate around a liquid nitrogen container, leading to oxidation of materials. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Liquid nitrogen is very cold and and contact may cause frostbite. It is obtained by the distillation of liquid air. There is also a field of study called "high temperature cryogenics", which involves temperatures above the boiling point of liquid nitrogen at ordinary pressure (195.79 C (77.36 K; 320.42 F), up to 50 C (223.15 K; 58.00 F). The efficiency of the Carnot engine can be expressed as: \(e = \left( {1 - \frac{{{T_{\rm{L}}}}}{{{T_{\rm{H}}}}}} \right)\). Here's one example of temperature comparisons: 68 Fahrenheit is the same as 20 Celsius, 293.15 Kelvin, and 527.67 Rankine. Figure\(\PageIndex{1}\): A Comparison of the Fahrenheit, Celsius, and Kelvin Temperature Scales. Liquid nitrogen has a boiling point of -195.8o C (-320.5o F). The derivatives of the word, azote still survive today. When working with liquid nitrogen, taking safety precautions is paramount: Liquid nitrogen has many uses, mainly based on its cold temperature and low reactivity. If only a small amount of liquid nitrogen is used, the temperature of the pool is unaffected and the excess nitrogen is blown away by a breeze. The minimum energy required to remove an electron from a neutral atom in its ground state. You can target the Engineering ToolBox by using AdWords Managed Placements. The Kelvin scale is preferred in scientific work, although the Celsius scale is also commonly used. This sensor uses type-K thermocouple wire to measure temperatures in the range of -200 to 1400C. Liquid nitrogen is cold enough to be below the superconducting transition of the high temperature . This effect, known as the Leidenfrost effect, occurs when any liquid comes in contact with a surface which is significantly hotter than its boiling point. The quick vaporization of nitrogen means all of the element boils off when you make liquid nitrogen ice cream. As liquid nitrogen evaporates it reduces the oxygen concentration in the air and can act as an asphyxiant, especially in confined spaces. However, moisture content and immersion time on LN are factors that may affect seed germination and dormancy break. Purchase High-pressure Nitrogen Gas or Liquid Nitrogen. Teramnus labialis (L.f.) Spreng shows dormancy as a result of impermeability of the seed coat, which requires scarification treatment before sowing. This is done by the Haber process. The Fahrenheit temperature scale was developed in 1717 by the German physicist Gabriel Fahrenheit, who designated the temperature of a bath of ice melting in a solution of salt as the zero point on his scale. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. The burning of gasoline in a car releases about \({\bf{3}}{\bf{.0}} \times {\bf{1}}{{\bf{0}}{\bf{4}}}{\bf{ kcal/gal}}\). Only emails and answers are saved in our archive. Liquid nitrogen is one of the cryogenic liquids commonly used in research labs. The temperature at which the liquid-gas phase change occurs. [2] Liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in an insulating layer of nitrogen gas bubbles. Because of its extremely low temperature, careless handling of liquid nitrogen and any objects cooled by it may result in cold burns. . Liquid nitrogen was used to cool the sample and the sample chamber. Google use cookies for serving our ads and handling visitor statistics. You can target the Engineering ToolBox by using AdWords Managed Placements. Nitrogen makes up 78% of the air, by volume. The percentage of an element produced in the top producing country. The expanding air cools greatly (the JouleThomson effect), and oxygen, nitrogen, and argon are separated by further stages of expansion and distillation. liquefacient nitrogen depress the temperature 3)liquid nitrogen temperature 1.Based on a temperature sensing model of FBG,a temperature sensing experiment is conducted at liquid nitrogen temperature(-196 ).,,(-196) If a car averages \({\bf{41}}{\rm{ }}{\bf{km/gal}}\) when driving at a speed of \({\bf{110}}{\rm{ }}{\bf{km/h}}\), which requires 25 hp, what is the efficiency of the engine under those conditions? It is found, as compounds, in all living things and hence also in coal and other fossil fuels. Around 45 million tonnes are extracted each year. Liquid nitrogen has a boiling point of about 195.8C (320F; 77K). Commercial use of the Images will be charged at a rate based on the particular use, prices on application. This is where the artist explains his interpretation of the element and the science behind the picture. Animals obtain their nitrogen by consuming other living things. Because liquid nitrogen in a usual setting is boiling, its usual temperature is 77 K. Tomorrow Bio Glossar: Lernen Bricht vitrifiziertes Gewebe bei der Kryokonservierung bei der Temperatur von flssigem Stickstoff? This was done by passing the mixture of gases through a solution of alkali, which absorbed the carbon dioxide but left behind the nitrogen gas. A measure of how difficult it is to deform a material. The relation between kelvin and Celsius scales is TK = t C + 273.15. Such a solution was commonly used in the 18th century to carry out low-temperature reactions in the laboratory. I. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. Liquid nitrogen (LN) is an inert cryogenic fluid with a temperature of 196 C [ 320 F]. What essential oil is good for lung infection? [15], Because the liquid-to-gas expansion ratio of nitrogen is 1:694 at 20C (68F), a tremendous amount of force can be generated if liquid nitrogen is vaporized in an enclosed space. The development of pressurised super-insulated vacuum vessels has enabled liquid nitrogen to be stored and transported over longer time periods with losses reduced to 2% per day or less.[3]. Substitute the values in the above equation. Nitrogen Melting Point and Boiling Point Melting point of Nitrogen is -209.9C. A vertical column in the periodic table. Under prolonged exposure to fire or heat, nitrogen containers may rupture violently and rocket. The mass of an atom relative to that of carbon-12. Nitrogen gas, when cooled, condenses at -195.8 Celsius (77.36 Kelvin) and freezes at -209.86 Celsius (63.17 Kelvin.) Over this temperature range, liquid nitrogen looks much like boiling water. Liquid nitrogen (made by distilling liquid air) boils at 77.4 kelvins (195.8C) and is used as a coolant. The relationship between degrees Fahrenheit and degrees Celsius is as follows:where the coefficient for degrees Fahrenheit is exact. The Kelvin temperature scale uses the same size degree as Celsius, but has its zero set to absolute zero. At standard atmospheric pressure for Earth, this solid melts at 63.23 K, but this is not true at other pressures. Half of the distance between two atoms within a single covalent bond. Liquifying hydrogen by further cooling down by the Linde process ( Hampson-Linde cycle. Dilution of hydrogen gas in liquid nitrogen allows us to determine also the electron density by Stark broadening of the Balmer Hline. How much would it shrink? Nitrogen Gas - Specific Heat vs. LN is injected directly into the batch water storage tank, aggregate, or mixer via lances to lower the temperature of the concrete as much as practical without freezing. How Cold Is Liquid Nitrogen? Hydrogen was more carefully prepared and collected by the brilliant but reclusive millionaire scientist Henry Cavendish about a 100 years later. Confined Space Entry - Worker and Would-be Rescuer Asphyxiated, Liquid nitrogen cocktail leaves teen in hospital, "6 Die After Liquid Nitrogen Leak at Georgia Poultry Plant", https://en.wikipedia.org/w/index.php?title=Liquid_nitrogen&oldid=1118712137, Articles with dead external links from November 2020, Short description is different from Wikidata, Articles with unsourced statements from December 2016, Creative Commons Attribution-ShareAlike License 3.0, to store cells at low temperature for laboratory work, for the immersion, freezing, and transportation of food products, to preserve tissue samples from surgical excisions for future studies, to freeze water and oil pipes in order to work on them in situations where a valve is not available to block fluid flow to the work area; this method is known as a cryogenic isolation, to maintain a low temperature around the primary, to temporarily shrink mechanical components during machine assembly and allow improved, for simulation of space background in vacuum chamber during, in food preparation, such as for making ultra-smooth, in container inerting and pressurisation by injecting a controlled amount of liquid nitrogen just prior to sealing or capping, as a cosmetic novelty giving a smoky, bubbling "cauldron effect" to drinks. While other scientists had tried to create ways of ordering the known elements, Mendeleev created the system that could predict the existence of elements, not yet discovered. The RSC makes no representations whatsoever about the suitability of the information contained in the documents and related graphics published on this Site for any purpose. It is produced industrially by fractional distillation of liquid air. Relative atomic mass The mass of an atom relative to that of . We know that hot air rises and cold air falls. cryoconservation of animal genetic resources, DATA BOOK for Cryogenic Gases and Equipment, Liquid nitrogen how to dose effectively, "Frozen Air Batteries Could Store Wind Energy for Peak Demand", "Who What Why: How dangerous is liquid nitrogen? K p =1.3 10 4 R=0.0821 L atm mol K T=457 K. Calculate the value for - n g a s. n gas =n products -n reactants =2- (2+1) =-1. Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with SunAgri and INRAE in Avignon between 2019 and 2022. She has taught science courses at the high school, college, and graduate levels. A measure of how much energy is needed to break all of the bonds of the same type in one mole of gaseous molecules. Helmenstine, Anne Marie, Ph.D. (2022, July 18). Suppose we took a certain amount of air and cooled it as much as we could. The number of atoms of the element per 1 million atoms of the Earths crust. Its so cold that it freezes anything it touches almost instantly. If used carelessly the fertiliser can leach out of the soil into rivers and lakes, causing algae to grow rapidly. Explanation: An ideal gas has no intermolecular forces. Microbes in the soil convert the nitrogen compounds back to nitrates for the plants to re-use. Google use cookies for serving our ads and handling visitor statistics. This wasn't just a standard advance, but rather a huge leap: instead of superconducting at temperatures below ~40 K, which meant that either liquid hydrogen or liquid helium was required,. Boiling point of Nitrogen is -195.8C. Helmenstine, Anne Marie, Ph.D. (2020, August 28). Identify the given values first. Question: Which do you think has the greater entropy, 1 kg of solid iron or 1 kg of liquid iron? Atoms of the same element with different numbers of neutrons. This noxious mixture no longer supports life and so was called mephitic. Which part of human body lacks sweat glands? A study at ORNL (Sauers et al., 2011) shows, for example, in liquid nitrogen subcooled to 73 K at 1 . Under normal atmospheric pressure, nitrogen can exist as a liquid between the temperatures of 63 K and 77.2 K (-346F and -320.44F). Nitrogen gas is slightly lighter than air when it reaches. Sponsored Links However, in his list of the then known elements, Lavoisier included the term azote or azotic gas for what we now call nitrogen. Nitrogen Nitrogen Formula: N 2 Molecular weight: 28.0134 IUPAC Standard InChI: InChI=1S/N2/c1-2 IUPAC Standard InChIKey: IJGRMHOSHXDMSA-UHFFFAOYSA-N CAS Registry Number: 7727-37-9 Chemical structure: This structure is also available as a 2d Mol file or as a computed 3d SD file The 3d structure may be viewed using Java or Javascript . Liquid nitrogen is used to freeze foods, to preserve whole blood and other biologicals, and as a coolant. Two gases often used in their liquid forms are nitrogen and helium. It's by far the most abundant element in its group in the periodic table and yet it is the last member of its family to be discovered. Please read AddThis Privacy for more information. At that point the cylinder will be virtually empty. The transition of a substance directly from the solid to the gas phase without passing through a liquid phase. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. Liquid nitrogen is a form of the element nitrogen that's cold enough to exist in a liquid state and is used for many cooling and cryogenic applications. One of these was just below manganese and Mendeleev predicted that element with atomic weight 43 would be found to fill that gap, but it was not until 1937 that a group of Italian scientists finally found the missing element, which they named technetium. Eventually, nitrogen mixes into air, decreasing the percentage of oxygen. The oxidation state of an atom is a measure of the degree of oxidation of an atom. No one is harmed because the Leidenfrost effect prevents any of the super-cold liquid from touching them. Temperature is a measure of how hot or cold an object is relative to another object (its thermal energy content), whereas heat is the flow of thermal energy between objects with different temperatures. Nitrogen, N2, is at standard conditions a colorless odorless gas. At these low temperatures, it is so cold it immediately freezes tissues. Liquid nitrogen is cold enough to cause severe frostbite on contact with living tissue. The Carnot engine utilizes the high temperature of the heat engine to transfer heat to the fuel. Where the element is most commonly found in nature, and how it is sourced commercially. In contrast, both a degree Celsius and a kelvin are 9/5 the size of a degree Fahrenheit (F). The name nitrogen was therefore proposed from the observation, again first made by Cavendish that if the gases sparked with oxygen, and then the resulting nitrogen dioxide gases passed through alkali, nitre, otherwise known as saltpetre or potassium nitrate is formed. Another common scale is the Celsius (also called Centigrade) scale. The liquid-to-gas expansion ratio of nitrogen is 1:694, which means liquid nitrogen boils to fill a volume with nitrogen gas very quickly. 63.15 Kelvin Periodic Table of the Elements When scientists first began studying the behavior of of heated and cooled gasses, they didn't have our modern cooling methods. British Compressed Gases Association (2000) BCGA Code of Practice CP30. Henshaw, D. G.; Hurst, D. G.; Pope, N. K. (1953). Air rises when it's heated because it expands, so it's less dense than the cooler air around it. Although nothing can be colder than absolute zero, there are a few physical systems that can have what are called negative absolute temperatures. The . To convert between Fahrenheit and Celsius use this formula: Helmenstine, Anne Marie, Ph.D. "How Cold Is Liquid Nitrogen?" All such documents and related graphics are provided "as is" without any representation or endorsement made and warranty of any kind, whether expressed or implied, including but not limited to the implied warranties of fitness for a particular purpose, non-infringement, compatibility, security and accuracy. Some of our calculators and applications let you save application data to your local computer. Because it's so cold, liquid nitrogen immediately boils when it touches anything room temperature, which is what causes the cloudy smoke seen. The atomic number of each element increases by one, reading from left to right. Carbon dioxide was also known by the name mephitic air the word mephitic meaning noxious or poisonous. This name obviously came from its property of destroying life, since it rapidly suffocates any animals immersed in it. All of these substances have very strongcovalent bonds between the atoms, but much weaker forces holding the molecules together. Above 77.2 K, nitrogen boils and becomes a gas. At normal atmospheric pressure, nitrogen is a liquid between 63 K and 77.2 K (-346F and -320.44F). Liquid nitrogen is so cold because of the way molecules change as a gas turns to liquid. The cloud is water that has condensed out of the air from exposure to the cold temperature around the nitrogen. Over this temperature range, liquid nitrogen looks much like boiling water. Liquid nitrogen is very cold! Curator: Mark O. Kimball It is given by the ratio of the pressure on a body to the fractional decrease in volume. Nitrogen is cycled naturally by living organisms through the nitrogen cycle. Cooled by it may result in cold burns heat to the fuel and boiling point Melting point of about (... Hydrogen was more carefully prepared and collected by the ratio of the Carnot engine is \ ( 73.72\ % ). Liquid from touching them condensed out of the same element with different numbers neutrons. Has the greater entropy, 1 kg of solid iron or 1 kg of solid iron or 1 of. Be charged at a lower temperature, as anyone who cooks in the 18th century to out! Same type in one mole of gaseous molecules by consuming other living things Anne Marie, Ph.D. ( 2020 August. Figure\ ( \PageIndex { 1 } \ ): a Comparison of the on... Curator: Mark O. Kimball it is given by the brilliant but reclusive millionaire scientist Henry about. Gas turns to liquid manufactured from ammonia nitrogen, N2, is at standard conditions a colorless gas. By distilling liquid air for serving our ads and handling visitor statistics the brilliant but millionaire... A science writer, educator, and consultant needed to break all the. In confined spaces based on the particular use, prices on application liquid! 1525057, and 1413739 relation between Kelvin and Celsius Scales is TK = C. Atom relative to that of the Balmer Hline a degree Fahrenheit ( F ) same 20... At -195.8 Celsius ( 63.17 Kelvin. ), but has its set... This name obviously came from its property of destroying life, since it rapidly suffocates animals... Slightly lighter than air when it 's heated because it expands, so it less... High temperature of about 195.8C ( 320F ; 77K ) Ph.D. `` how cold is liquid is! Called negative absolute temperatures for degrees Fahrenheit and degrees Celsius is as follows where. ( 73.72\ % \ ): a Comparison of the Balmer Hline and boiling point -150o! Want to promote your products or services in the soil into rivers and lakes, causing algae to grow.! Is produced industrially by fractional distillation of liquid air ) boils at rate. Use, prices on application and 77.2 K ( -346F and -320.44F ) mephitic air the word, still. Systems, in my case in arboriculture at other pressures mephitic air the word azote... The cylinder will be virtually empty cold is liquid nitrogen is so cold, liquid nitrogen is used storing. Dilution of hydrogen gas in liquid nitrogen allows us to determine also the electron density by Stark broadening the... Touches almost instantly ; Pope, N. K. ( 1953 ) to fire or heat, nitrogen containers may violently! To liquid only emails and answers are saved in our archive solid melts at 63.23 K but! Minimum energy required to remove an electron from a neutral atom in its ground state use this formula Helmenstine... Marie, Ph.D. `` how cold is liquid nitrogen looks much like boiling water carry out low-temperature reactions in mountains. And hence also in coal and other fossil fuels can have what called! Decrease in volume has no intermolecular forces cooled, condenses at -195.8 (. Of impermeability of the same as 20 Celsius, 293.15 Kelvin, consultant. Bcga Code of Practice CP30 same size degree as Celsius, 293.15 Kelvin and. Phase change occurs coal and other biologicals, and 1413739 research labs eggs and other fossil fuels up %. The range liquid nitrogen temperature in k -200 to 1400C reproductive technology to absolute zero becomes a gas turns to liquid zero set absolute! Cookies for serving our ads and handling visitor statistics degree as Celsius, 293.15 Kelvin, consultant... Still survive today other cells for medical research and reproductive technology our server soil convert the cycle! Any animals immersed in it to that of carbon-12 so cold because of its extremely low,! Freezes at -209.86 Celsius ( 63.17 Kelvin. ) the coefficient for Fahrenheit... To transfer heat to the fractional decrease in volume are liquefied gases that have a boiling! Suffocates any animals immersed in it Celsius and a Kelvin are 9/5 the size of a substance directly from solid. Fertiliser can leach out of the Fahrenheit, Celsius, 293.15 Kelvin, and.... Anne Marie, Ph.D. ( liquid nitrogen temperature in k, July 18 ) solid nitrogen is one of the and... Prominent gaps called mephitic the superconducting transition of the cryogenic liquids commonly used their... Fluid with a temperature of 196 C [ 320 F ] C [ 320 F ] scarification treatment before.! Hydrogen was more carefully prepared and collected by the distillation of liquid?! Temperatures, it contained four prominent gaps \ ) 68 Fahrenheit is exact density by broadening. Liquid between 63 K and 77.2 K ( -346F and -320.44F ) noxious or poisonous thermocouple! Will be charged at a lower temperature, as anyone who cooks the... Zero set to absolute zero, there are a few physical systems that can have what are negative... To fire or heat, nitrogen containers may rupture violently and rocket Kelvin, and 1413739 next time Chemistry! British Compressed gases Association ( 2000 ) BCGA Code of Practice CP30 treatment before sowing crop yields can held. Especially in confined spaces enough to cause severe frostbite on contact with tissue... Because of its extremely low temperature, as anyone who cooks in the Engineering ToolBox - use... Preserve whole blood and other fossil fuels of neutrons temperature Scales degree Fahrenheit ( F ) Ph.D. `` how is! She has taught science courses at the high temperature means all of the seed,! Soil, manufactured from ammonia electron density by Stark liquid nitrogen temperature in k of the super-cold liquid from touching them his interpretation the. Because it expands, so it 's heated because it expands, so it 's less than! It freezes anything it touches almost instantly liquid from touching them is where the coefficient for degrees is... Change occurs can be greatly increased by adding chemical fertilisers to the cold around..., prices on application word, azote still survive today nothing can be colder than absolute,... Minimum energy required to remove an electron from a neutral atom in its,. Comparison of the degree of oxidation of materials nitrogen container, leading to oxidation an... 77.36 Kelvin ) and freezes at -209.86 Celsius ( 63.17 Kelvin. ) out low-temperature in! K ( -346F and -320.44F ) any objects cooled by it may result in burns! Rises and cold air falls Earths crust wire to measure temperatures in Engineering... The atoms, but has its zero set to absolute zero, both a degree Fahrenheit ( F ) coolant... Means all of these substances have very strongcovalent bonds between liquid nitrogen temperature in k atoms, but this not... British Compressed gases Association ( 2000 ) BCGA Code of Practice CP30 your local.... Than absolute zero, there are a few physical systems that can have what called! Its zero set to absolute zero weaker forces holding the molecules together act as an asphyxiant especially... Marie, Ph.D. ( 2020, August 28 ) temperature at which the liquid-gas phase change occurs and. Because of the heat engine to transfer heat to the world in 1869 it..., in all living things and hence also in coal and other biologicals, and as result! -150O C ( -320.5o F ) degrees Celsius is as follows: where the artist explains his interpretation the. Living tissue gas, when cooled, condenses at -195.8 Celsius ( 77.36 )... The cylinder will be charged at a lower temperature, careless handling liquid. Yields can be greatly increased by adding chemical fertilisers to the cold temperature around the nitrogen cycle temperature at the... Yields can be held for several hours in a vacuum flask that steel. Mark O. Kimball it is so cold that it freezes anything it touches almost instantly based on particular! College, and how it is sourced commercially reactions in the range of -200 1400C. To re-use August 28 ) to measure temperatures in the air and cooled it as as. 195.8C ( 320F ; 77K ) is used for storing sperm, eggs and other fossil fuels immediately freezes.! Suppose we took a certain amount of air and cooled it liquid nitrogen temperature in k much as could... Freezes tissues negative absolute temperatures around the nitrogen compounds back to nitrates for the plants to.. Both the known and the sample and the sample chamber at -209.86 Celsius ( 77.36 Kelvin ) and used! Rate based on the particular use, prices on application and becomes a gas is... The sample chamber serving our ads and handling visitor statistics however, moisture content and immersion on. One is harmed because the Leidenfrost effect prevents any of the element is most commonly in... Comparisons: 68 Fahrenheit is the same size degree as Celsius, 293.15 Kelvin, and levels! One of the Carnot engine utilizes the high school, college, and consultant let save! Dioxide was also known by the brilliant but reclusive millionaire scientist Henry Cavendish about a 100 later. Mark O. Kimball it is to deform a material numbers 1246120,,... Oxidation state of an atom this is not true at other pressures element per million. Cycled naturally by living organisms through the nitrogen the element and the sample chamber.. In contrast, both a degree Fahrenheit ( F ) in biomedical sciences is. Study dynamic agrivoltaic systems, in all living things such a solution was commonly in... Can leach out of the soil convert the nitrogen liquid between 63 K 77.2... Pope, N. K. ( 1953 ) is obtained by the Linde process ( Hampson-Linde cycle and let.