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  • Derived from "Nitre".
  • Discovered by Daniel Rutherford.
  • Atomic number=7
  • Atomic mass = 14 amu.
  • Diatomic molecule .
  • Valency=3.
  • Isotopes: , .
  • Present in in periodic table. elements are called pnicogens and their compounds are called pnictides.
  • Electronic Configuration: .
  • Nitrogen shows anomalous behaviour. Reasons:

i) Small Size

ii) high value of electronegativity.

iii) non-availability of d-orbitals.

iv) ease of multiple bond formation.

  • Occurrence

-It is present in air.

-It occurs as Nitrates (Chile Saltpetre) and (Salt petre).

-Present in the form of Protein.

Difference between Nitrogen and other elements of group :

  • is gas while others are solid.
  • is diatomic while others are tetra atomic except Bismuth .
  • forms bonding while (Phosphine), (Arsine), etc do not form H-bond.
  • Nitrogen is relatively inert among its members of family.
  • Nitrogen shows wide range of oxidation states to .

Preparations of Nitrogen:

1) By heating ammonium nitrate or ammonium dichromate: 

2) By heating urea with Nitrous acid or alkaline hypobromide:

3) By oxidation of :

4) When sodium or barium azide is heated in small quantity then pure Nitrogen is obtained.


Note: is manufactured by Fractional Distillation Method.

      Properties of Nitrogen:


  - It is colourless, tasteless and odourless.

  - Due to it’s triple bond heat of dissociation is very large.


   1) With oxygen:

-The cycle of nitrogen is called nitrogen cycle.

-This process is called denitrification.

2) Reaction with metals:

3) With Calcium Carbides:



-Used in manufacture of etc.-Used in filling electric bulb because of it’s inert nature.

Oxides of Nitrogen

1) – Nitric Oxide

-It is odd electron molecule .

- It is paramagnetic in nature and is diamagnetic in liquid and solid due to formation of dimer .

 2) –Nitrogen Dioxide

-Colour: Orange

-Value of angle is 134 .

-It is also paramagnetic in nature.

3) –Dinitrogen Oxide

 - It is also called laughing gas.

 - It is soluble in water but not in hot water.

 4) – Dinitrogen Trioxide

- Also called nitrogen sesquioxide or nitrogen anhydrite.

5) –Dinitrogen Pentoxide

-It is ionic solid in solid state but asymmetrical molecule in vapour state.

Compounds of Nitrogen

 1)Ammonia :

    Lab preparation

-When ammonium salt is heated with a base then ammonium gas is obtained in lab.

Note : It can also prepared by the action of and .

-Obtained gas is dried by passing through quick lime and collected in an inverted in gas jar by the downward displacement of air.

Manufacture of Ammonia

 Ammonia gas can be manufactured by following process :

   1) Haber’s process


  2) Cyanamide process

 3) Serpeck’s process

 Properties of Ammonia:

Physical Properties:

- It has pungent smell.

- It is highly soluble in water giving an alkaline solution.

- It is also called tear gas.

-The liquid ammonia boils at and freezes at .

Chemical Properties:

  1) Basic Nature


2) Self-ionization


3) acts as Lewis base.

4) Reaction with alkali metals.

- can displace from ammonia.

5) With

- oxidized to .

- is catalytically oxidized to .

6) With

7) Test reaction:

    a) using Nessler’s reagent

    b) With Mercurous Nitrate paper


Used to manufacture urea, nitric acid and used as refrigerant.

 Test of Ammonia

1) It gives yellow ppt with chloroplatinic acid .

            2) ( Nitric Acid)

Lab Preparation

-When sodium nitrate is heated with in a glass retort nitric acid is obtained.


1) Ostwald process:

-Catalyst used is at .

   2) Brikland-Eyde process

Properties of Nitric acid

Physical properties

-It’s b.p is and F.P is .-It is colourless liquid.

Chemical properties:

1) Action on metal:

a) :



Note : Similar reaction with .

b) :

i) with gives .

     ii) with gives .

     iii) with gives .

 Note : , and also react with in same manner.

            But gives with .


i) reacts with gives .

    ii) react with   gives .

iii) With gives .

Note: and react with in same manner.


i)   gives .

    ii) gives .


      To Summarize:

i) Generally with gives .

 Exception: ang gives .

ii)gives .

iii) give .

Exception: give .

iv) give .

v) give .

5) also oxidizes with non metals, metalloids and compounds.

6) Oxidizes Sugar into Oxalic acid and gives .

Uses :

-To prepare explosives, dyes, drugs, fertilizers.

-Used in purification of gold and Silver, Nitration of Organic compounds.