high class, easy and good slide to be viewed. best in quality and easy to understand. Thank you for selecting this and good luck.

1. AMRITA VIDYALAYAM, KANYAKUMARI

2. S.NO Content Page No
1 Certificate 2
2 Acknowledgement 3
3 Aim / Objective 4
4 Introduction 5-7
5 principle 8-10
6 Materials required 11
7 Procedure 12-14
8 Observation 15-16
9 Conclusion 17
10 Bibliography 18

3. This is to certify that J.SANJEEBAN, A student of Class XII has
successfully completed the research on the topic“Study thechange in
E.M.F of a Danielcell Due to variousfactorssuch as Changein
concentration,temperatureAndArea of electrodes.”
Under the guidance of MRS. S.ANITHA (SUBJECT TEACHER) during
the year 2018 -2019 in the partial fulfillmentof CHEMISTRY
PRACTICAL EXAMINATION.
Teacher’s signature Principal’s signature
Date School Rubber Stamp

4. Primarily I would thank god for being able to complete this
project with success.Then I would like to thank my physics
teacher MRS. S.ANITHA , whose valuable guidance has been the
one that helped me patch this project and make it full proof
success, her suggestions and her instruction, has served as the
major contribution towards the completion of the project.
Then I would like to thank my parents and friends who
helped me with their valuable suggestions and guidance has been
helpful in various phases of the completion of the project.
I would like to extend my full gratitude to our principal
Mr. PRADEESH, for providing me with all the facility that was
required.

5. StudythechangeinE.m.fofaDanielcellDuetovarious
factorssuchasChangeinconcentration,temperature
AndAreaofelectrodes.

6. ELECTROCHEMICAL CELLS:
An electrochemicalcell is a device by which electric current
energy is generated at the cost of chemical energy due to
chemical action taking place in the cell. They are of two types,
1. Primary cells
2. Secondary cells
PRIMARY CELLS: It is a cell in which electrical energy is
produced due to chemicalenergy. The chemical reaction in the
cell is irreversible
E.g: Daniel cell, Voltaic cell, Leclanche cell
SECONDARY CELLS: It is a cell in which the electrical energy
is first stored up as a chemical energy and when the outside
circuit is closed to draw the current from the cell the stored
chemical energy is reconverted into electrical energy. The
chemical reactions are irreversible in this cell.

7. The secondary cells are also called storage cell or
accumulators.
E.g: Lead acid accumulator,Edison cell
Here we are going to discuss about the change in emf of the
Daniel cell which is a primary cell, with respect to
concentrationand temperature.

8. E.M.F [ELECTROMOTIVE FORCE]
Electromotiveforce, also called emf, is the voltage developedby any
source of electrical energy such as battery or dynamo.
EMF of cell means, when current flows through two points a
potential difference generated by a cell draws no current is called
EMF.
Inside a source of EMF that is open-circuited, theconservative
electrostaticfield created by separation of charge exactly cancels
the forces producing the EMF. Thus, the emf has the same value
but opposite sign as the integral of the electric field aligned with
an internal path between two terminals A and B of a source of emf
in open circuit condition.

9. DANIELCELL:
The Daniel cell is a typed electrochemicalcell invented in 1836
by John Frederic Daniel. A British chemist and meteorologist
and cons sled of a copper pot tilled with a copper sulfate
solution. In which was immersed an unglazed earthenware
container filled with sulfuric acid and a zinc electrode. He was
searching for a way to eliminatethe hydrogen bubble problem
found in the voltaic pile and his solution was to use a second
electrolyte to consume the hydrogen produced by the first Zinc
sulfate may be substituted for the sulfuric acid. The Daniel cell
was a great improvementover the existing technology used in
the early days of battery developmentA later variant of the
Daniel cell called the gravity cell or crowfoot was invented in
the 1860s by a Frenchman named Callaud and became a
popular choice for electrical telegraphy.

10. The Daniel cell is also the historical basis for the contemporary
definition of the volt which is the unit of electromotiveforce in
the InternationalSystem of Units. The definitions of electrical
units that were proposed at the 1881 International Conference
of Electricianswere designed so that the electromotiveforce of
the Daniel cell would be about 1.0 volts. With contemporary
definitions. the standard potential of the Daniel cell at 25'C is
actually 110 V
In the Daniel cell copper and zinc electrodes are immersed in a
solution of copper(II) sulfate and zinc sulfate respectively.At
the anode. Zinc is oxidized per the following half reaction.
Zn(s) • 2n2•(aq) • 2e- (Standard electrode potential
--0. 7618 V I At the unlock. copper is reduced per
the following react on. Cu2•1aq) • 2e-
Cuts.(Standard electrode potential .0,340 V I
The total reaction being
Zn9s) • Cu2•(aq) * Zn2. (ag) • Cu(s)..( Open circuit
voltage 1.1018 V )

11. FEATURESOF DANIELCELL:
• Zinc rod at which oxidation occurs is called the anode
while the copper rod at which the reduction takes place is
called cathode.
• The half-cell reaction occurring at anode is called
oxidation -half cell reactionwhile the occurring at cathode
is called reduction.
• The two half-cell reactions always take place
simultaneously i.e.... Half-cell reaction cannot take place
immediately.
• Since electrons are produced at zinc electrode.It is
rich in electrons and pulls these electrons into the
external circuit and hence acts as negative pole.The
copper electrode on the other hand is deficient in
electrons and thus pulls the electrons fromthe external
circuit and act as positive pole.
• The electrons flowfromnegative pole to positive pole
in the external circuit. However,conventionally the
current is said to flowin opposite direction i.e. from
positive pole to negative pole in the external circuit.

12. • The concentration of copper sulphate solution
decreases with passage of time as the cell operates.
Consequently the current fall with passage of time.
TWO BEAKERS U TUBE
COPPER ROD ZINC ROD

13. COPPER SULPHATE ZINC SULPHATE
DIAGRAM:

14. Salt Bridge:
It consists of a tube filled with semi-solid paste
obtained by adding gelative or agar to the
solution of strong electrolyte such as NS.
NH4NO3 KNO3 etc. which does not change
chemically during that process. Function of salt
bridge.
• To complete the electrical circuit by allowing
the solution to Low from one solution to another-
Without mixing the two solutions.
• To maintain electrical neutrality of solution in
two half cells.
Procedure :

15. 1. Take two and pour the required chemicals in
respective beaker and mark them for
identification.
2. Take two square to slide in and connecting
wire to their screw.
3. Connect negative of the voltmeter to the
anode and it’s positive to cathode.
4. Take filter paper long enough to dip into both
the solution. Dip the paper on KNo3 solution and
put it as a salt bridge.
5. Put on the electrode voltmeter set up. Note
the reading quickly and the put of the electrode
voltmeter set up.
6. For measuring variation with temperature,
with change in area of electrode use the different
size of electrode and then do step 5 again.
7. For measuring variation with temperature
heat the solution and then do step 5 again.

16. 8. For measuring variations with change in
concentration of electrolyte .Use the electrolytes
of different molarity and then do step 5 again
Variation with Concentration:
 Fixed Temperature = 28oC
Molarity
of
CuSO4(M)
Molarity
of
ZnSO4(M)
Voltmeter Reading
(V)
1M 1M 1.1
0.1 M 0.1 M 1.078
1M 0.1M 1.080

17. Variation in Temperature:
 Constant Molarity = 0.1 M
.
Variation in Area:
 No changes in change in EMF.
Temperature
of CuSO4 (co)
Temperature
of ZnSO4 (co)
Voltage
(V)
30 30 1.078
70 70 1.098
100 100

18. 1) Decrease in concentration increase in EMF of
the cell.
2) Increase in Temperature, increase in EMF.
3) Change in area does not have any change in
EMF.

19.  Websites:
 WWW.Slideshare.com
 www.academia.edu
 Help from Teachers:
 Mrs. S. Uma