This document provides an overview of electrochemistry and electrochemical cells. It defines electrochemistry as the branch of chemistry dealing with the relationship between electrical energy and chemical change. An electrochemical cell is a device that uses a chemical change to produce electricity or uses electricity to produce a chemical change. The document describes the components of electrochemical cells, including electrodes and electrolytes. It distinguishes between galvanic cells, which produce electricity from chemical reactions, and electrolytic cells, which use electricity to drive chemical reactions. Examples of the significance of electrochemistry include metal refining and batteries.

1. B.ED., PRACTICAL EXAMINATION
(2019 – 2021)
LEVEL - I
K. DEEPIKA
1122119BD027

3. Contents:
✓ Electrochemistry
✓ Electrochemical cell
✓ Components of electrochemical cell
✓ Types of electrochemical cell
- Galvanic cell
- Electrolytic cell
✓ Significance of electrochemistry

4. How does
battery
produce
electricity?
Because,battery
contains some
chemicals in it.

5. ✓ The chemical reactions (chemical energy) that take place in the battery
produce electricity (electrical energy).
✓ Scientists realized that chemical energy can be converted into
electrical energy and vice versa.
✓ Another branch of applied chemistry is evolved - Electrochemistry.
✓ Electrochemistry is the branch of chemistry which deals with the
relation between electrical energy and chemical change.
✓ It mainly concerned with the process taking place between the
electrode and solution having ions called electrolyte.

6. Electrochemical Cell
✓ The device that make use of a chemical change to produce electricity or
electricity to produce chemical change is called Electrochemical cell.
Use chemical change Produce Electricity
Use Electricity Produce Chemical change
Components of Electrochemical Cell
✓ Electrode
✓ Electrolyte

7. Electrode
❑Solid electrical conductor made of
metal (sometimes non-metal like
graphite).
❑A cell consists of two electrodes –
Anode, Cathode.
Electrolyte
❑Solution made up of ions or molten
salts which can conduct electricity.

8. Cell reactions
An electrochemical cell involves two reactions simultaneously.
Oxidation – Loss of electron, it takes place at anode.
Metal Metal ion + electron (e-1)
Reduction – Gain of electron, it takes place at cathode.
Metal ion + electron (e-1) Metal
Since both the reactions take place simultaneously, the interconversion of
electrical and chemical energy in electrochemical cells involves a
redox reaction.

9. Types of Electrochemical cell
Classified based on nature of conversion as,
- Galvanic Cell
- Electrolytic cell
Galvanic cell
✓ It is an electrochemical cell which converts chemical energy into
electrical energy.
✓ It produces electricity from chemical reactions.
✓ It consists of two half cells namely anodic half – cell and
cathodic half - cell

10. ✓ In anodic half-cell, the anode is in contact with its electrolyte whereas
in cathodic half-cell the cathode is in contact with its electrolyte.
✓ The anode and cathode are connected by a conductor wire.
✓ The electrolytes of half-cells are connected through a tube containing
a saturated salt solution. It is called Salt-bridge.
✓ In galvanic cell, both the half cells are kept separately but stay
connected electrically.
Working of Galvanic cell
✓ At anode, oxidation takes place which releases electrons .
✓ Electrons attracted by cathode and hence electrons flowing from
anode to cathode are gained in reduction reaction.
✓ As long as the redox reaction proceeds, there is a flow of electrons
and hence electricity

11. Electrolytic cell
✓ It is an electrochemical cell which converts
electrical energy into chemical energy into
chemical energy.
✓ In electrolytic cells, electricity is used to bring
about the chemical reactions.
✓ Here, both anode and cathode are in contact with
the same electrolyte and thus the half-cells are not
separated.
✓ In Galvanic cell electricity is produced, but in
electrolytic cell, electricity is used to produce
chemical reaction.

12. ✓ In electrolytic cells, when electricity is passed to the
electrolyte, it dissociates into its constituent ions.
✓ These ions undergo redox reaction forming the
respective elements. This phenomenon is called
Electrolysis.
✓ Electrolysis is a process by which an electrolyte is
decomposed into its constituent elements by
passing electricity through its aqueous solution or
fused state ( molten state).

13. Significance of electrochemistry
✓ It is used in the electrorefining of many non- ferrous metals.
✓ The production of high-purity lead, zinc, aluminium, and copper
involves the use of electrolytic cells.
✓ Metallic sodium can be extracted from molten sodium chloride by
placing it in an electrolytic cell and passing an electric current through
it.
✓ Many commercially important batteries are made up of galvanic cells.
✓ Fuel cells are an important class of electrochemical cells that serve as a
source of clean energy in several remote locations.