Which is inert in its elemental state, yet powerful enough to make explosives? Which element is poisonous in one state, while vital in another? What element is found in chicken and Windex? Nitrogen. Nitrogen, in its elemental form and its compounds, is one of the most common elements in the world. It is found in as diverse products as fertilizer, hams, gunpowder, air-bags, window cleaners, beef, and detonators. Nitrogen in each of these products represents a different oxidation state. The number of an oxidation state is the difference of electrons the nitrogen has from normal, nonionized nitrogen gas. A positive number indicates a loss of that amount of electrons, while a negative number indicates a gain of that many electrons.
The first oxidation state is the negative 3 state. Ammonia is an example of it. Ammonia is a colorless gas with an irritating, pungent odor. It is a weak reducing agent (a chemical that gives away electrons; a weak one would give away electrons to a small extent). Chlorine gas can reduce it, while oxygen reduces it with difficulty. The reason is that it needs to give away three electrons to be reduced. It tends to be difficult to give away that many electrons. Ammonia is used in fertilizers, cleaners, and the production of nitric acid.
The second state is the negative 2 state. Hydrazine is an example. It is a liquid that has an ammonia-like smell. It is dangerous in its pure form. When it is mixed with an oxidizing agent such as nitric acid or hydrogen peroxide, it can react dangerously. Aqueous solutions are much more stable since it dilutes the reactive nitrogen ions. It is used as a rocket fuel.
The third state is the negative 1 state. Hydroxylamine is an example. It is a colorless crystalline substance. It is a powerful reducing agent that can explode upon heating. It is used in organic synthesis to make amine and amide groups, which are found in proteins and medicines, for example.
The fourth state is the negative 1/3 state. Sodium azide is an example. It is the most powerful reducing agent. It can donate electrons to any metal compound and produce the pure metal from it. Many azides explode upon heating, releasing nitrogen gas and a metal. It is used in bomb detonators and airbags.
The reason that the reduction potential is stronger the lower the negative number gets, is that it is easier to release one electron than to release two or three electrons. This makes it a much stronger reducing agent. What makes these compounds liable to be reduced is that nitrogen gas is very stable.
The fifth state is the 0 state, nitrogen gas. It is very unreactive. It is used as an inert atmosphere for low temperatures, since many metals can oxidize it to the negative three state when heated red-hot. It is also used, liquefied, as a refrigerant.
The sixth state is the positive 1 state. Nitrous oxide is an example. It is a sweet, pleasant-smelling gas which is generally unreactive. When it is heated strongly, it decomposes into nitrogen and oxygen. It is used as a propellant in food products and as an anesthetic.
The seventh state is the positive 2 state. Nitric oxide is an example. It is a poisonous colorless gas which is a weak reducing agent. It is not normally an oxidizing agent. It is reduced readily by oxygen (it gives away electrons somewhat readily). It is used as an antibacterial agent in the human body and is a step in the production of nitric acid.
The eighth state is the positive 3 state. Sodium nitrite is an example. Sodium nitrite, used in the preservation of processed meats, is a poisonous colorless crystalline solid. It is a reactive oxidizing agent, and can be used to make azides from hydrazine.
The ninth state is the positive 4 state. Nitrogen dioxide is an example. It is a brown, toxic, choking gas. It is produced by reduction of the nitrate ion most commonly. It is used to make nitric and sulfuric acids.
The last state is the positive 5 state. Potassium nitrate is an example. It is a colorless crystalline solid. When molten, it is a strong oxidizing agent. It is the chief oxidizing agent in gunpowder.
Nitrogen takes on many oxidation states. Some are very reactive, while some are very unreactive. It has more states than almost any other element. It is therefore a fundamental element, vital to human life.
Note: This paper was made when I was not so good in chemistry.