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2. Assignment / Presentation : Application of electrolysis
Course : Science 2
Semester : 3rd
Roll no : 13
Submitted by : kifayat ullah mian
Submitted to : Dr. Romman khan
Date : :

3. What is electrolysis?
• Electrolysis is the breaking down of an ionic
substance using electricity. The substance that
is broken down is called the electrolyte.
• Electrolysis is the process of electrically
inducing chemical changes in a conducting
melt or solution e.g. splitting an ionic
compound into the metal and non-metal.

4. • An ionic substance contains
charged particles called
ions. An ion is an atom that
has gained or lost electrons
and so carries a positive or
negative charge.
Al
Al3+
Aluminium atom
loses 3
electrons
Aluminium ion

5. electrolysis of Water

6. ConduCtor versus
eleCtrolyte
• An electrolyte is a solution that can conduct
electricity due to ions present in it. What is the
difference between a conductor and an
electrolyte?

9. • In a conductor, electrical current is flowing
through the material in its solid form.
Conductors are generally metals. On the other
hand, an electrolyte can carry current in its
molten state or in a solution form.

10. •AppliCAtions of
eleCtrolysis

11. ElEctroplating
• Electroplating is the process
involving electrolysis to plate, or
coat, one metal with another or a
plastic with a metal. Often the
purpose of electroplating is to
give a protective coating to the
metal beneath. For example,
bath taps are chromium plated to
prevent corrosion, and at the
same time are given a shiny and
more attractive.

12. • The article to be plated is made the cathode in
the cell so that the metal ions move to it when
the current is switched on. The cathode
reaction in this process is:
• silver ions + electrons  silver atoms
Ag+
(aq) + e–
 Ag (s)

13. ElEctro-rEfining of
mEtals
• Similar to the process of electro-deposition,
electrolysis can be used to purifying
metals that are obtained from the ores. The
process is known as electro-refining of
metals. The metals that are generally refined
by this process are Zn, Ag, Ni, Cu, Pb,
Al, etc.

14. • It is used electrolytic cell for purifying metal
ores, in this case the metal is impure copper.
• The electrolyte dissociated into
CuSO4  Cu 2+
+ SO4
2-
Reaction at the cathode
Cu 2+
+ 2 e-
 Cu
Reaction at the anode
Cu  Cu 2+
+ 2 e-

15. Extraction of sodium
• Sodium, a very reactive metal, was first
discovered by Sir Humphry Davy in 1807.
• It is now extracted by electrolysing molten
sodium chloride in the Down's cell. Sodium
chloride may be obtained from the evaporation
of sea water or mined as rock salt

16. • The chloride ions are attracted to the anode,
where they lose electrons and
form chlorine gas.
• chloride ions  chlorine molecules +
electrons
The overall reaction is
• 2 NaCl (l)  2 Na (l) + Cl2 (g)

17. Aluminum Production by
ElEctrolysis
Name of the Ore imported from (Guinea and Brazil)
• Bauxite
Al2O3.3H2O
Heating drives off the water
• Al2O3.3H2O + Heat → Al2O3 + 3H2O
Melting point of Bauxite is 2045 0
C
Cryolite is added
Lowers the melting point to 1000 0
C

18. rEfErEncEs
1. W. Crookes “The Chemical news of industrial
science with which is incorporated the Chemical
gazette” A journal of practical chemistry in all its
applications to pharmacy, 294-299 (2011).
2. S. Lee “Sustainable production of formic acid by
electrolytic reduction of gaseous carbon dioxide” J.
Mater. Chem, 3, 3029-3034 (2015).
3. H. Ju “Electro-catalytic conversion of ethanol in
solid electrolyte cells for distributed hydrogen
generation” Electrochimical, 212, 744–757 (2016).