source :

Chemical properties:

1. Combustion:

when mixture of NH3 and O2 burns, it gives N2 gas.

4NH3 + 3O2  ——–> 2 N2  + 6H2O

2. Basic nature:

a) Aqueous solution of NH3 is NH4OH which is base & turns red litmus blue.

NH3 +H2O ——> NH4OH

b) Ammonia reacts with acid to form salt:

NH3 +HCl ——–>  NH4Cl

2NH3 + H2SO4 ——-> (NH4)2SO4

NH3 + HNO3 —–> NH4NO3 (Ammonium nitrate)

c) There is one lone pair of electron present on nitrogen atom of NH3. Therefore NH3 acts as electron pair donor and is a Lewis base.

:NH3 (Lewis base)

d) Reaction with halogens :

i) Reaction with chlorine :

When chlorine reacts with excess of ammonia then nitrogen & ammonium chloride is formed.

2NH3 +3 Cl2 ——> N2 + 6HCl

6HCl + 6 NH3 ——> 6NH4Cl

Reaction as a whole,

8NH3 + 3Cl2 ——> N2 + 6NH4Cl

when excess of  chlorine  reacts with ammonia then Nitrogen tri chloride is formed.

NH3 + 3Cl2 ——–> NCl3 (explosive) + 3HCl

ii) Reaction with Bromine:

2NH3 + 3Br2  ———> N2 + 6HBr

6HBr + 6NH3 ——-> 6NH4Br

Reaction as a whole is ,

8NH3 + 3Br2 —–> N2 + 6NH4Br

iii) Reaction with Iodine:

NH3 + I2 ———-> NH3.NI3 +NH4I

NH3.NI3 ——-> NH4I +N2 +I2

e) Reaction with CuO or PbO:

2NH3 +3 CuO ———> 3Cu + N2 +3H2O

3PbO +2NH3 ——–> 3Pb +N2 +3H2O

f) Reaction with FeCl3:

FeCl3 + 3NH4OH  ——>Fe(OH)3 (red-brown precipitate of ferric hydroxide) +3NH4Cl

g) Reaction with CrCl3:

CrCl3+ 3NH4OH  ——–> Cr(OH)3 [chromium hydroxide(insoluble)]+ 3NH4Cl

we know that Cr(OH)3 has green precipitate.

h) Reaction with AlCl3:

AlCl3 + 3NH4OH ——-> Al(OH)3 (white precipitate of Aluminium hydroxide) +3NH4Cl

i) Reaction with AgCl:

with small amount of NH4OH precipitate comes out which is soluble in excess of NH4OH due to complex formation.

2AgCl + 2NH4OH ——-> Ag2O +H2O + 2NH4Cl

Ag2O + NH4OH +NH4Cl ———> [Ag(NH3)2]Cl   [diamine silver (I) chloride (soluble complex)]+H2O

j) Reaction with AgNO3:

AgNO3 + 2NH4OH ——->[ Ag(NH3)2 ]NO [diamine silver(I) nitrate] + 2H2O

k) Reaction with Copper sulphate:

with the small amount of NH4OH, blue  precipitate of  cupric hydroxide is obtained. Which is soluble in excess  of NH4OH due to formation of soluble complex.

CuSO4 + 2NH4OH ——–> Cu(OH) [blue precipitate ]+(NH4)2SO4

Cu(OH)2 + 2NH4OH + (NH4)2SO4 ——>[ Cu(NH3)4 ]SO4 + 4H2O

[Cu(NH3)4]SO4 is tetra amine copper (II) sulphate (Soluble blue complex).

l) Reaction with ZnSO4:

ZnSO4 + 2NH4OH ——–> Zn(OH)2 (white precipitate) + (NH4)2SO4

Zn(OH)2 + 2NH4OH + (NH4)2SO4 ——->[ Zn(NH3)4]SO4 + 4H2O

[Zn(NH3)4]SO4 is tetra amine zinc (II) sulphate (soluble colorless complex).

m) Reaction with ZnCl2:

ZnCl2 + 2NH4OH ——–> Zn(OH)2 +2NH4Cl

Zn(OH)2 + 2NH4OH +2NH4Cl ——->[ Zn(NH3)4 ]Cl2   + 4 H2O

[Zn(NH3)4 ]Cl2 is tetra amine  zinc (II) chloride (soluble colorless complex).

n) Reaction with CdSO4:

CdSO4 + 2NH4OH ——-> Cd(OH)2 +(NH4)2SO4

Cd(OH)2 + 2NH4OH +(NH4)2SO4 —–>  [ Cd(NH3)4]SO4 + 4H2O

[Cd(NH3)4 ]SO is tetra amine cadmium (II) sulphate (soluble colorless complex).

o) Reaction with Mercurous chloride:

Black residue  of mercuric amino chloride and mercury is obtained.

Hg2Cl2 +2 NH4OH ——-> Cl-Hg-NH2 (mercuric amino chloride)+ Hg + 2H2O +NH4Cl

p) Reaction with mercuric chloride:

HgCl2  + 2NH4OH ——–> Cl-Hg-NH2 (white color) +NH4Cl + 2H2O