Oxides of Nitrogen

Nitrogen Oxide Chemical Formula

Nitrogen oxides are a mixture of the nitrogen and oxygen composed gases. Nitric oxide (NO) and nitrogen dioxide (NO2) are two of the most significant toxicologically important compounds. Other gases in this group are nitrogen monoxide (or N2O), and nitrogen pentoxide (NO5). A number of nitrogen oxides are formed by nitrogen reacting with oxygen. It exhibits various oxidation states, ranging from +1 to +5 in its oxide forms. Nitrogen oxides having nitrogen in the higher state of oxidation are more acidic than those in the lower state of oxidation. Nitrogen dioxide is produced for the manufacturing process of nitric acid. Most nitric acid is used in fertiliser manufacturing, while some are used in explosives manufacturing for both military and mining uses. Let us find out more about the oxides of nitrogen in detail.

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Names of Oxides of Nitrogen

Let us now look at nitrogen oxide formula and about the different types of names of oxides of nitrogen: -

  1. Dinitrogen Oxide 

Dinitrogen oxide is a colourless, non-flammable gaseous compound. It has neutral properties. It's usually referred to as laughing gas. Dinitrogen oxide is formulated by decomposition of ammonium nitrate at high temperatures.

NH4NO3 → 2H2O + N2O

  1. Dinitrogen Trioxide 

Dinitrogen trioxide is a deep blue, acidic solid. It can only be insoluble at low temperatures, i.e. in liquid and solid phases. As temperature rises, the equilibrium leads to the formation of the constituent gases. Dinitrogen trioxide is prepared by mixing equal parts of nitric oxide and nitrogen dioxide and by further cooling the mixture below −21 ° C. 

NO + NO2 → N2O3

  1. Nitrogen Monoxide 

Nitrogen monoxide is a colourless gas. Its bond structure includes a valence electron, and it belongs to a class of diatomic molecules. Nitrogen monoxide is prepared by reducing the dilute nitric acid with copper.


3H2SO4 + 2NaNO2 + 2FeSO4  →   2NaHSO4 + Fe2(SO4)3 + 2H2O + 2NO

  1. Nitrogen Dioxide 

Nitrogen dioxide is a reddish-brown poisonous gas with a pungent smell, and contributes greatly to air pollution all around the world.   It is acidic in nature with +4 nitrogen oxidation state. Nitrogen dioxide is formulated by thermal decomposition of metal nitrate.

2Pb(NO3)2 →  4NO2 + 2PbO  + O2

  1. Dinitrogen Tetroxide 

Dinitrogen tetroxide is a colourless solid that is in equilibrium with nitrogen dioxide. It is an efficient oxidising agent which is used as a solvent for the production of many chemical substances.

N2O4 ⇌ 2NO2

  1. Dinitrogen Pentoxide 

Dinitrogen pentoxide is a colourless solid. It undergoes sublimation marginally above room temperature. It is an erratic and potentially dangerous oxidising agent. It has been used as a solvent diluted in chloroform for nitration. Dinitrogen pentoxide is produced by the process of dehydration of nitric acid (HNO3) with phosphorus (V) oxide.

Solved Examples

Q1) What are the industry and natural sources for the emission of oxides of nitrogen? 

Answer) The industry sources of nitrogen include oil and gas extraction, the supply of electricity, mining, manufacturing industries and petroleum manufacturing.

The natural sources for the emission of nitrogen include: Biological nitrogen recycling involves processes that produce nitric oxide and nitrous oxide as intermediates. Thermal processes in the atmosphere which take place during lightning or wildfires also produce nitrogen oxides.

Q2) What are the ways to reduce nitrogen oxide emissions to treat the pollution of air? 

Answer) The ways to reduce the emission of nitrogen oxide are: 

  1. Using a limited quantity of nitrogen fertilisers 

  2. Using catalytic converters in cars to reduce emissions 

It can be done in two ways: 

  • Reduction 

Removal of oxygen from the nitrogen oxide 

  • Oxidation 

Adding oxygen to carbon monoxide to form carbon dioxide, which is less harmful than carbon monoxide.

Q3) What are some applications of Nitrous Oxide? 

Answer) Some applications of Nitrous Oxides are:

  • Used for sedation in dentistry 

  • Used as analgesic to control pain 

  • It is extremely safe does not react with body fluids 

  • Decreases anxiety 

  • Rapid and onset recovery

FAQ (Frequently Asked Questions)

1. What are the effects on health due to nitric acid?

Low levels of nitrogen oxides can cause irritation of the eyes, nose, throat, and lungs, probably leading to coughing, shortness of breath, fatigue as well as nausea. Exposure may also lead to fluid build-up in the lungs 1-2 days after exposure. Breathing high levels of nitrogen oxides can cause rapid burning, convulsions and swelling of tissues in the throat and upper respiratory tract, reduced oxygenation and may even lead to death in certain cases.

The role of nitric oxide in the thinning of blood vessels makes it an important controller of blood pressure. Nitric oxide is also generated by nerve cells and is used by the nervous system for neurotransmission. It involves controlling functions ranging from digestion, blood flow, memory, and vision.

2. What are the effects of Nitric acid in our environment?

Nitrogen oxides are part of the biogeochemical cycle of nitrogen and are present in the air, soil, and water. In the atmosphere, nitrogen oxides are rapidly balanced in a state of equilibrium to nitrogen dioxide (NO2), which eventually produces acidic rain. Nitrogen oxides play a crucial role in maintaining ozone levels in the stratosphere. Ozone is formed by a photochemical reaction between nitrogen dioxide and oxygen.

Excess quantities of nitrogen oxides, specifically nitrogen dioxide (NO2), can lead to death in plants and roots and damage the leaves of several crop plants. NO2 is a harmful component of photochemical smog. High amounts increase the concentration of acid in the rain (lower pH) and therefore lower the pH of surface and groundwater and soil due to acid rain which is not sustainable for the plants in order to survive.

Increased levels of atmospheric nitric oxide generated from the industrial activity are still one of the causes of the progressive depletion of the ozone layer in the upper atmosphere. Sunlight allows nitric oxide to react chemically with ozone (O3), which transforms ozone to molecular oxygen (O3).