1. HYDROGEN
RESEMBLANCE OF ALKALI METAL
Electronic Configuration
Formation of Mono Electropositive
Reducing Nature
Oxidation State
2. RESEMMBLANCE WITH HALOGEN
Electronic configuration
Ionisation enthalpy
Formation of Uninegative ion
Non metallic character
Diatomic Nature
Formation of ionic compound
3. Difference in the properties of hydrogen
from Alkali metal & halogen
Nature of oxide
Unshared pair of electrons
Nature of compounds
Size of ions
4. Isotopes of hydrogen
Protium (1 Proton)
Deuterium (1Proton & 1Neutron)
Tritium (1 Proton &2 Neutron)
Difference in the properties of an element
due to the difference in atomic mass is called
isotopic effect
5. ELECTROLYSIS OF WATER
On passing electric current in acidulated or
alkaline water ,water dissociate to give
hydrogen at cathode and oxygen at anode
4H2O -----4H+ +4OH-
4OH - ----- 2H2O+O2
4H + ---- 2H2
6.
7. From Barium Peroxide
This is a method for laboratory
preparation of Hydrogen
Peroxide. Hydrated Barium
Peroxide must be used,
anhydrous barium peroxide will
form a protective layer and not
react with the sulphuric acid. The
resulting H2O2 is a 5%
concentrate solution.
BaO2.8H2O + H2SO4 → BaSO4 +
H2O2 + 8H2O
8. From Sodium Peroxide
Here too we will use a dilute
solution of Sulphuric Acid and
gradually dissolve sodium
peroxide in it. As you know
H2O2 is explosive at high
temperatures, so we use cold
sulphuric acid. On reacting these
two we get crystals of Sodium
Sulphide and a 30% solution of
hydrogen peroxide. We can
perform vacuum distillation on
the said solution to get pure
hydrogen peroxide
Na2O2 + H2SO4 → Na2SO4 + H2O2
9. When H2O2 serves as
an oxidizing agent, the
oxygen of hydrogen
peroxide (that is
present in -1 oxidation
state) is reduced to
H2O (-2 oxidation
state).
H2O2 + 2H+ + 2e –> 2H
2O
10. When H2O2 (-1 oxidation
state)serves as areducing
agent, the oxygen of H2O2
is oxidized to O2 ( 0
oxidation state) and
bubbles are noticed. As a
reducing agent:
2 KMnO4 + 5 H2O2 + 3 H2S
O4 --> K2SO4 + 5 O2 + 2 Mn
SO4 + 8 H2O
or
2 MnO4- + 5 H2O2 + 6 H+ --
> 5 O2 + 2 Mn2- + 8H2
11. If you look at the dot
diagram of H2O2 you will
see the O-O bond. And you
will see that both oxygen
atoms have two pairs of
unbound electrons each.
This brings into effect the
valence shell electron
repulsion theory.
13. The properties of hydrogen
peroxide are as
follows: Hydrogen
peroxide is almost colorless
(very pale blue) in a pure
state. Its boiling point has
been extrapolated at a
temperature as high as
150.2 C which is almost 50
C higher than the boiling
point of water. The melting
point of hydrogen
peroxide is -0.43 C.
Editor's Notes
From Barium Peroxide
This is a method for laboratory preparation of Hydrogen Peroxide. Hydrated Barium Peroxide must be used, anhydrous barium peroxide will form a protective layer and not react with the sulphuric acid. The resulting H2O2 is a 5% concentrate solution.
BaO2.8H2O + H2SO4 → BaSO4 + H2O2 + 8H2O
] From Sodium Peroxide
Here too we will use a dilute solution of Sulphuric Acid and gradually dissolve sodium peroxide in it. As you know H2O2 is explosive at high temperatures, so we use cold sulphuric acid. On reacting these two we get crystals of Sodium Sulphide and a 30% solution of hydrogen peroxide. We can perform vacuum distillation on the said solution to get pure hydrogen peroxide
Na2O2 + H2SO4 → Na2SO4 + H2O2 (30%)
When H2O2 serves as an oxidizing agent, the oxygen of hydrogen peroxide (that is present in -1 oxidation state) is reduced to H2O (-2 oxidation state).
H2O2 + 2H+ + 2e –> 2H2O
When H2O2 (-1 oxidation state)serves as areducing agent, the oxygen of H2O2 is oxidized to O2 ( 0 oxidation state) and bubbles are noticed. As a reducing agent:
2 KMnO4 + 5 H2O2 + 3 H2SO4 --> K2SO4 + 5 O2 + 2 MnSO4 + 8 H2O
or
2 MnO4- + 5 H2O2 + 6 H+ --> 5 O2 + 2 Mn2- + 8H2
If you look at the dot diagram of H2O2 you will see the O-O bond. And you will see that both oxygen atoms have two pairs of unbound electrons each. This brings into effect the valence shell electron repulsion theory.
Structure of hydrogen peroxide
The properties of hydrogen peroxide are as follows: Hydrogen peroxide is almost colorless (very pale blue) in a pure state. Its boiling point has been extrapolated at a temperature as high as 150.2 C which is almost 50 C higher than the boiling point of water. The melting point of hydrogen peroxide is -0.43 C.
