This is the story of nitrogen, a significant element, a powerful element, and an often misunderstood or underestimated element. Nitrogen is one of the many elements on the Periodic Table. Like all the rest, nitrogen has its own set of unique properties, compounds, and features. This element plays an important role in modern technology and science. Although the average person may not know it, nitrogen is responsible for many things we take for granted. This element is especially important because of where it is applied. Even though this element may not be as popular as other elements such as hydrogen, oxygen, helium, or even carbon, it plays a major part in life, the environment, industry, and basically almost everything else. We might not know it, but we owe a lot to nitrogen.
Nitrogen has a history that dates back to more than 1,000 years. It is an interesting story of various civilizations’ contributions to recognizing and understanding this element throughout human history. One of the first nitrogen compounds to be discovered was what was called saltpeter or also known as niter. The first known experimentations with nitrogen were done by the Chinese. They tried mixing substances together so they can live forever. They also believed it would help them make gold. When they mixed saltpeter and sulphur, then set it on fire, the mixture exploded. This is how the Chinese got the idea for firecrackers. Yet, no one realized that the saltpeter contained nitrogen. Before modern elements were discovered, people generally thought that there were 4 elements – earth, water, fire, and air. Thus, no one thought that the air was made up of more than one component. This was so until a Chinese man name Mao-Khoa wrote that air contains what is called yin and yang. Khao described yang as being perfect by itself because it did not react with other things. This sound a lot like nitrogen. Khoa also stated that yin was an incomplete air that was sucked into a burning material. This description seems very similar to that of oxygen which is part of the air and does get sucked into a burning material. Mao-Khoa’s findings never reach Europe however. Although the Europeans remained unaware of the two parts of the air, they did know of the firecrackers, and by the 900’s the Chinese were using their knowledge to launch arrows against enemies. These were the first cannons and guns which were worked by exploding the black powder. This knowledge of gunpowder quickly spread through the Middle East to Europe. Europeans also learned that niter had another important use, when added to crops it made them grow larger and faster. It is then that people started to study nitrogen more and discovered other nitrogen compounds such as nitric acid. In the early 1700’s a scientist name Stephen Hale studied smoky fumes given off by various chemical reactions. Hale knew that a flame would not light up in the air remaining after a candle had burned in a small space. Hale believed that the air was somehow “infected” and thus would not light up the candle. This is so because the flame had consumed all of the oxygen of course. Although he did not realize it, Hale’s infected air was nitrogen. At that time many other scientists were experimenting with nitrogen such as Henry Cavindish. During the 1770’s Cavindish discovered a difference between nitrogen and carbon dioxide. Carbon dioxide was absorbed by lye but nothing at that time could absorb nitrogen. At that time Joseph Priestly stated that nothing known could absorb this “strange air”. In 1772 the two chemists that are credited with the discovery of nitrogen published their results. Daniel Rutherford – a Scottish chemists distinguished nitrogen from carbon dioxide the same way that Cavindish. The other was Carl Wilhelm Scheele – a Swedish chemist who did other test that showed the same thing. Scheele was the first to name nitrogen. Because fire and animals could not live in it he called it “foul air” or rotten air. He discovered that nitrogen makes up for about 80 percent of the atmosphere, the other air he called “fire air” because fire and animals could live in it ; this air was oxygen. Antoine Lavoiser was a French chemist that first claimed that nitrogen was an element in 1789. More than one element had already been found in earth at that time, thus the four element idea was slowly fading away. Lavoiser announced that there were more than 30 elements at that time including hydrogen, oxygen, and nitrogen. Lavoisier called nitrogen: azote, which in means “no life” in Greek. Nitrogen is still called azote in France today. It was Cavendish who discovered that nitrogen was in niter and nitric acid. After hearing this, a French chemist named Jean-Antoine Chaptal suggested that “foul air” be called nitrogen which means generator of niter. Thus, nitrogen has a long and interesting history. If it wasn’t for the studies and experiments done by the early scientists and chemists we would not be as advanced as we are today.
Datacomments / Extra Information
Atomic Number7( 7 protons in nucleus )
antimony, and bismuth. Each element in this groups has 5 electrons in its outer shell.
Known stable isotopesN14 and N15 N14 = 99.63 % , N15 = 0.37%
Known Radioactive isotopesN12, N13, N16, N17Extremely short half-lives measured in seconds or minutes
Boiling point-195.8 C
Melting Point-209.86 C
Critical temperature-147.1 C
Critical pressure33.5 atmospheres
density 1.14 g/cm3 (solid)If air has a density of 1.0000 , nitrogen is .9675.
Solid structureNitrogen has a hexagonal crystal structureIn order for nitrogen to be solid, the temperature must be extremely low, and the pressure very high.
Atomic Radius70 pmCovalent radius, in picometers
Ionic Radius of N(III)30 pmThis data is for a coordination type ion 6 which is octahedral and has a low spin.
Ionization enthalapy number 1402.3 kJ mol-1First ionization enthalapy number
Electron Negativity3.04Pauling Scale
Chemical Compounds – FluoridesNClF2 , NF3 Example –
N2 + 3F2 2NF3
Chemical Compounds – ChloridesNClF2 , NCl3 Example -
N2 + Cl2 + 2F2 2NClF2
Nitrogen has become to be known as a somewhat “shy” gas. It does not like to mingle, group, or socialize with other elements or compounds. This is so because nothing burns or lives in it and it is not absorbed by anything. Yet nitrogen is not really that shy and can be very reactive. Some basic physical properties of nitrogen is that nitrogen at standard conditions is a colorless, odorless, and tasteless gas. Nitrogen is slightly soluble in water ( 2.35 part nitrogen in 100 parts water at 0 degrees C ) , this solubility decreases as the temperature decreases3. Besides this nitrogen, is insoluble with most other known liquids.
In terms of chemical composition, nitrogen is diatomic. Thus the formula for nitrogen gas would be N2. One nitrogen atom has 5 electrons in its outer shell. Thus the nitrogen atom binds with another nitrogen atom to share 3 electrons. Now the outer shell is satisfied and N2 is very stable. These formulas describe some oxidation potentials of nitrogen :
1)-.80V : H2N2O2 + 2H2O 2HNO2 + 4H+ + 4e-
2)-.81V: N2O4 + 2H2O 2NO3 + 4H+ + 2e-
On Earth, Nitrogen is quite abundant. In fact, without nitrogen, there would be no life. Nitrogen does not appear among the first 37 elements found in igneous rock in the Earth crust. It ranks 16th in abundance in seawater with an estimated 2,300 tons of nitrogen per cubic mile of seawater. In terms of abundance in the Universe, nitrogen ranks seventh, where hydrogen ranks 1st. Although nitrogen may be lacking in the earth’s crust or other places, it more than makes up in the atmosphere. Of dry air in the atmosphere, 78.09% is nitrogen by volume and 75.54% by weight. Thus, nitrogen makes up around 80% of the air. interestingly, nitrogen makes up less than 3% of Mar’s atmosphere. This is because while Earth was forming, the early volcanoes spewed nitrogen into the air to form the atmosphere.
There are two main methods of nitrogen lab preparation. The first method is separation of elementary nitrogen from the atmosphere. Nitrogen is collected from the air in areas without pollution. The industrial method of separating nitrogen from the air is through fractional distillation of liquid air. The air contains a mixture of gases but mainly nitrogen. All the other gases such as argon and oxygen boil off leaving liquid nitrogen1. The second method of preparing nitrogen in the lab is through the decomposition of nitrogen compounds. The following table shows the different methods of preparing nitrogen in the lab through reactions of different nitrogen compounds.
Description of ReactionEquation
A saturated solution of sodium nitrite is mixed with a saturated solution of ammonium chloride.NH4 + NO2 N2 + 2H2O
Ammonia is oxidized by passing through bromine water,
the resulting mixture is separated by a series of reagents.2NH3 + 3Br2 N2 + 6H + Br
Thermal decomposition of sodium azide or barium azide. Ba(N3)2 Ba + 3N2
The reaction of sulfamic acid (urea) with nitrite ion.NH2SO3H + NO2 N2 + HSO4 + H2O
Nitrogen has many uses. The two major sections of nitrogen uses are biological and industrial. In the biological world, all living things are dependent on nitrogen. Nitrogen is used to build protein and amine groups which make up amino acids, which in turn make up DNA, RNA, and other nucleic acids. The only problem is that nitrogen is diatomic and there is hardly anything that can break up the two atoms of nitrogen. Fortunately there is bacteria that “fix” the nitrogen by either converting ammonia to nitrogen or making nitrates. This is all part of something called the nitrogen cycle. First the nitrogen is fixed and used by an animal to make protein. Then that animal dies, or the protein is removed as waste. Then bacteria decompose the waste, and the cycle starts all over again. In the industrial world, however, nitrogen has different uses. Nitrogen compounds such as potassium nitrate are used for fertilizers. There is an abundance of nitrate in Chili for fertilizers. Liquid nitrogen is used to build pressure up in crude oil wells to force oil up. Nitrogen is sometimes used as a refrigerant for the transportation and immersion freezing of foods. Nitrogen provides an inert atmosphere for electronic furnace operations and for gaseous insulations of transformers. Nitrogen gas is also used for nitriding certain alloy steels. Thus, nitrogen is important to both business and life.
Nitrogen provides many useful compounds. One of the most important compounds of nitrogen is ammonia. The formula for ammonia is NH3. Ammonia is used for artificial fertilizers, explosives, and resins. Another important compound of nitrogen is nitric acid which is HNO3. This is a very strong acid that eats through metals. This compound is used for dyes, explosives, and other fertilizers. One more important compound of nitrogen is nitrous oxide or N2O. This is commonly referred to as laughing gas, but it is also used to stop pain in certain minor operations. Yet, nitrogen and oxygen do not make a safe couple because of the electron configuration. That is why many explosives such as TNT, and nitroglycerine rely on nitrogen, oxygen, and another group. When nitrogen and oxygen break their unstable bonds, energy is released and an explosion occurs.
In conclusion, nitrogen is an element that holds an important scientific value, business value, and environmental value. This element has great destructive power and great healing power. Uses of nitrogen has helped us develop as a planet, and newer found uses will probably help us develop even more in the future.