Oxidation Number of Nitrogen in NO2 (Nitrogen Dioxide)

Nitrogen dioxide (NO2) is a molecule which contain two oxygen atom and one nitrogen atom. Oxidation number of nitrogen atom can be found by two methods, algebra method and observing structure of molecule. Oxidation number of nitrogen is important to decide to whether NO2 can be oxidized or reduced.



Oxygen is more electronegative than nitrogen. Therefore, electrons of N-O bonds are attracted towards oxygen atom.

Therefore, oxygen gets more electrons and we call oxygen atoms gets a negative oxidation number. Also, nitrogen loses electrons and call, nitrogen atom get a positive oxidation number.



oxidation number of nitrogen in NO2


Find oxidation number of nitrogen by observing the lewis structure

When you draw the best lewis structure of NO2, you can determine oxidation number of nitrogen atom NO2.

NO2 lewis structure

  • Oxidation number due to bonds: There is a double bond and single bond around nitrogen atom. Those bonds are made with oxygen. Therefore, electrons of bonds are attracted towards oxygen atom. Due to double bond and single bond, there are three bonds. For these three bonds, nitrogen has given three electrons to make those bonds. So, those three electrons are lost to nitrogen atom and oxidation number will be three due to bonds.
  • Oxidation number due to charge: Because there is +1 charge on nitrogen atom, it should be counted for overall oxidation number.

overall oxidation number = Oxidation number due to bonds + Oxidation number due to charge


overall oxidation number of nitrogen in NO2 = +3 + (+1) = +4

Find oxidation number of nitrogen in NO2 from algebra method

In this method, we are going to use known oxidation numbers in thhe molecule to find out unknown oxidation number of a atom in the same molecule. Usually oxygen's most common oxidation number is -2. But, nitrogen has so many oxidation numbers from -3 to +5. Therefore, we are going to find oxidation number of nitrogen using oxidation number of oxygen atoms (-2) .


  • NO2 is a neutral molecule. So, there is no overall charge.
  • Therefore, summation of oxidation numbers of all atoms in the molecule is zero.

Oxidation number of nitrogen + summation of oxidation numbers of two oxygen atoms = 0

  • x + (-2)*2 = 0
  • x = +4

Oxidation number of nitrogen in NO2 is +4.





Questions asked by students

Ask your question and find the answer free.

What are the reactions of increasing the oxidation number of nitrogen in NO2

Reaction between nitrogen dioxide and water: Here oxidation number of nitrogen is increased to +5 (HNO3) and reduced to +2 (NO).



Give some compounds which have oxidaion number higher than NO2 considering nitrogen

The only oxidation number which is higher than in NO2 is +5. As examples, HNO3 and N2O5 caan be given.




Can I say NO2 is acidic by looking the oxidation number of nitrogen?

We know nitrogen dioxide is acidic compound. Also, we know when oxidation number of an element is increased in a series of that element's oxides, acidic characteristics are increased. Nitrogen's maximum is oxidation number is +5. In nitrogen dioxide, oxidation number of nitrogen is +4 which is close to maximum oxidation number of nitrogen. Therefore, NO2 should have acidic characteristics.



What is the other oxide of nitrogen which has the same oxidation number as NO2

Dinitrogen tetroxide (N2O4) is the oxide of nitrogen which has the same oxidation number as NO2.



What can you decide by looking oxidation number of nitrogen in nitrogen dioxide?

Oxidation number of nitrogen in NO2 is +4. We know, nitrogen can show oxidation numbers from -3 to +5. Therefore, nitrogen atom in nitrogen dioxide has the capability of oxidizing and reducing. As an example, in the reaction of nitrogen dioxide and water reaction, nitrogen atom is oxidized to +5 oxidation state (nitric acid).

Also, because oxidation number of nitrogen is high positive value (+4), NO2 is an acidic oxide of nitrogen

oxidation number of N in NO2

Oxidation number of N in NO2 is +4. NO2 is an example for +4 oxidation state of nitrogen. Due +4 oxidation number, NO2 is an acidic gas. Usually, when an oxide of an element's oxidation number increases, acidic characteristics increases.





Related Tutorials








Lewis Structures of Molecules