ADITYA VIDYASHRAM RESIDENTIAL

SCHOOL PUDUCHERRY

ELECTROCHEMICAL
CELLS

DONE BY: -
V.INIYAVAN
XII-J1
 TABLE OF CONTENTS

S.no. CONTENTS Page

no.
1. INTRODUCTION 1
2. OBJECTIVE 2
3. THEORY 3-4
4. MECHANISM 5-7
5. OBSERVATION 8-9
6. EXPERIMENTAL PROCEDURE 10
7. REACTIONS AND EQUATIONS 11
8. CONCLUSION 12-13
9. APPLICATIONS 14-16
10. BIBLIOGRAPHY 17-18
 “SAMRAKSHANA”
The Total Protection with Affection

ADITYA VIDYASHRAM RESIDENTIAL SCHOOL

Poraiyur, Villianur, Puducherry – 605110

CBSE - SSCE: XII 2024-2025

CHEMISTRY-043

SENIOR SECONDARY CERTIFICATE EXAMINATION

PROJECT

CERTIFICATE

Name: Class & Sec:

Registration Number:

Title of the project:

Certified that this is a bonafide project work done by the above mentioned student in our school
during Senior Secondary course, in the year 2024-2025

SUBJECT TEACHER PRINCIPAL

Project Submitted for the CBSE- SSCE Practical Examination held on / /2025

INTERNAL EXAMINER EXTERNAL EXAMINER

 Acknowledgement
I would like to extend my sincere and heartfelt obligation towards all
those who have helped me in making this project. Without their
active guidance, help, cooperation and encouragement, I would not
have been able to present the project on time.

I am extremely thankful and pay my sincere gratitude to my teacher

For valuable guidance and support for
completion of this project.

I extend my sincere gratitude to my Principal

For the moral support extended

during tenure of this project.

I also acknowledge with a deep sense of reverence, my gratitude

towards my parents, other faculty members of the school and friends
for their valuable suggestions given to me in completing the project.

Date:
Place: Signature of the Student
 CERTIFICATE
This is to certify that the project work on
based on the curriculum of
CBSE has been completed by of Class-XII of
Aditya Vidyashram Residential school , Puducherry.

The above mentioned project work has been completed under my

guidance during the academic year 2024-25.

Signature of the guide teacher

INTRODUCTION:-

Electrochemical cells are fundamental components in the study of electrochemistry,

which bridges the gap between chemistry and electricity. An electrochemical cell
converts chemical energy into electrical energy through redox reactions. These cells
are pivotal in various applications, from powering everyday batteries to serving as
analytical tools in electrochemical measurements. The history of electrochemical cells
dates back to the late 18th century with the invention of the voltaic pile by Alessandro
Volta, marking a significant advancement in the field of electrochemistry. This early
invention laid the foundation for modern battery technology and electrochemical
studies.
Electrochemical cells can be broadly classified into galvanic (voltaic) cells and
electrolytic cells. Galvanic cells generate electrical energy from spontaneous chemical
reactions, whereas electrolytic cells use electrical energy to drive non-spontaneous
chemical reactions. Understanding these cells involves studying the electrochemical
series, cell potentials, and the Nernst equation, which collectively help predict and
analyze the behaviour of these cells under various conditions.
The study of electrochemical cells not only illuminates fundamental chemical
processes but also leads to practical applications in energy storage, corrosion
prevention, and electroplating. This project aims to explore the principles,
mechanisms, and practical applications of electrochemical cells, providing insight into
their operation and significance in both theoretical and practical contexts.

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OBJECTIVE:-

The primary objective of this project is to investigate and document the principles and
applications of electrochemical cells. The specific aims include:

1. Understanding Cell Design and Function: To examine the construction and

operation of different types of electrochemical cells, including galvanic and
electrolytic cells. This involves understanding the roles of electrodes,
electrolytes, and cell components in the generation and utilization of electrical
energy.
2. Determining Cell Potentials: To measure and analyze the cell potentials of
various electrochemical cells using standard electrode potentials and the Nernst
equation. This involves calculating the cell potential under different conditions
and interpreting the results in the context of redox reactions.
3. Exploring Electrochemical Reactions: To investigate the types of reactions
that occur in electrochemical cells, including oxidation and reduction
processes. This includes analyzing the reaction mechanisms and the impact of
various factors on the efficiency of these reactions.
4. Evaluating Practical Applications: To explore the real-world applications of
electrochemical cells, such as in batteries, corrosion prevention, and
electroplating. This involves understanding how electrochemical principles are
applied in these technologies and assessing their impact on technology and
industry.
5. Conducting Experimental Studies: To perform experiments on
electrochemical cells, including constructing and testing different cell types.
This includes documenting experimental procedures, observations, and results
to gain hands-on experience with electrochemical concepts.

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THEORY:-

An electrochemical cell is a device that converts chemical energy into electrical

energy through redox reactions. It consists of two half-cells connected by a salt bridge
or a porous membrane, which allows for the flow of ions while preventing the direct
mixing of the cell’s components. Each half-cell contains an electrode and an
electrolyte. The key components and processes involved in electrochemical cells
include:
1. Electrodes: These are conductive materials that facilitate the transfer of
electrons between the chemical substances and the external circuit. There are
two types of electrodes:
• Anode: The electrode where oxidation occurs (loss of electrons). In a
galvanic cell, it is the negative electrode, and in an electrolytic cell, it is
the positive electrode.
• Cathode: The electrode where reduction occurs (gain of electrons). In a
galvanic cell, it is the positive electrode, and in an electrolytic cell, it is
the negative electrode.
2. Electrolytes: The electrolytes are solutions or molten substances that conduct
electricity due to the movement of ions. Each half-cell contains its specific
electrolyte, which participates in the redox reaction by providing ions that
migrate through the salt bridge.
3. Salt Bridge: This is a tube filled with a gel or liquid containing an electrolyte,
such as potassium nitrate. The salt bridge allows the flow of ions between the
two half-cells, maintaining electrical neutrality and completing the circuit. It
prevents the direct mixing of different solutions in the half-cells, which could
otherwise lead to a precipitation reaction.
4. Redox Reactions: The operation of an electrochemical cell is based on redox
(reduction-oxidation) reactions. In the oxidation reaction, electrons are released
at the anode, and in the reduction reaction, electrons are gained at the cathode.
The flow of electrons through the external circuit from the anode to the cathode
generates electric current.
5. Cell Potential (Electromotive Force, EMF): The cell potential is the
difference in electrical potential between the two electrodes. It is determined by
the standard electrode potentials of the half-reactions. The cell potential can be
calculated using the Nernst equation, which takes into account the
concentration of ions in the electrolytes and the temperature.

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 6. Nernst Equation: The Nernst equation provides a quantitative measure of the
cell potential under non-standard conditions. It is expressed as:

7. Faraday’s Laws of Electrolysis: These laws relate the amount of substance

transformed at an electrode to the quantity of electricity passed through the
cell:
• Faraday's First Law: The mass of a substance altered at an electrode is
directly proportional to the amount of electricity passed through the cell.
• Faraday's Second Law: The mass of different substances altered by the
same quantity of electricity is proportional to their equivalent weights.
Understanding these principles provides insight into how electrochemical cells operate
and how they can be utilized for various applications, such as batteries, electroplating,
and corrosion prevention. The efficiency and effectiveness of these cells depend on
optimizing the components and conditions to maximize the cell potential and
minimize energy losses.

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MECHANISM:-

The mechanism of an electrochemical cell involves a series of well-defined steps and

principles:
1. Redox Reactions:
• Oxidation Reaction: Occurs at the anode where electrons are released.
For example, in a zinc-copper cell:

Zinc metal loses electrons and becomes zinc ions, releasing electrons into the external
circuit.
• Reduction Reaction: Occurs at the cathode where electrons are gained.
For example:

Copper ions in the solution gain electrons and are deposited as copper metal on the
electrode.

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2. Electron Flow and Electrical Circuit:
• External Circuit: Electrons flow from the anode to the cathode through
an external wire, creating an electric current. This flow of electrons
powers electrical devices connected to the circuit.
• Internal Circuit: The movement of ions in the electrolyte completes the
circuit internally. Cations move towards the cathode, and anions move
towards the anode to balance the charge.
3. Salt Bridge or Porous Membrane:
• Function: The salt bridge or membrane allows the flow of ions between
the half-cells, maintaining electrical neutrality and preventing charge
buildup. It typically contains a salt solution or gel that facilitates ion
transfer.
• Types: Common salt bridge materials include agar-agar or a solution of
potassium nitrate (KNO₃) in a gel. The choice of material depends on
the specific cell setup and requirements.

4. Nernst Equation:
• Purpose: The Nernst equation calculates the cell potential under non-
standard conditions, taking into account the concentrations of reactants
and products.

• Applications: The Nernst equation helps in predicting the voltage of a

cell based on varying concentrations of the reactants and products,
allowing for precise control and optimization of cell performance.

5. Faraday’s Laws of Electrolysis:

• First Law: The amount of substance transformed at an electrode is
proportional to the quantity of electricity passed through the cell.

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• Second Law: The quantities of different substances transformed by the
same quantity of electricity are proportional to their equivalent weights.

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OBSERVATION:-

During the experimentation with electrochemical cells, several observations are

typically made:
1. Cell Potential Measurements: The potential difference between the two
electrodes is measured using a voltmeter. This value indicates the driving force
of the redox reaction and provides insight into the cell's efficiency.
2. Electrode Behaviour: Changes in the appearance and behaviour of the
electrodes are noted. For instance, the anode may undergo corrosion or
dissolution, while the cathode may show signs of deposition or plating.
3. Electrolyte Changes: Observations regarding changes in the electrolyte
solution, such as color changes or the formation of gas bubbles, are recorded.
These changes can indicate the progress of the redox reactions and the
formation of by-products.
4. Current Flow: The flow of current through the external circuit is monitored,
and its consistency is checked. Variations in current flow can reveal issues such
as incomplete reactions or resistance in the circuit.
5. Yield and Efficiency: The efficiency of the cell in terms of energy conversion
and reaction completeness is evaluated. This includes assessing the yield of
desired products and the overall performance of the cell.

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Detailed Observations:
1. Electrode Behaviour:
o The zinc electrode undergoes noticeable corrosion, with a decrease in its
mass over time as it dissolves into the electrolyte.
o The copper electrode gains mass due to the deposition of copper ions
from the solution.
2. Electrolyte Changes:
o The blue color of the CuSO₄ solution decreases as copper ions are
reduced at the cathode and deposited onto the copper electrode.
o The concentration of Zn²⁺ ions in the ZnSO₄ solution increases as zinc
metal oxidizes and dissolves into the solution.
3. Current Flow:
o The current flow starts at a certain value and may vary slightly due to
changes in the electrolyte concentration and electrode surface area over
time.
4. Final Observations:
o The cell potential may slightly decrease as the reaction progresses due to
changes in ion concentrations and the formation of by-products.

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EXPERIMENTAL PROCEDURE:-

1. Materials and Setup: Gather materials including electrodes (such as copper

and zinc), electrolyte solutions (like copper sulfate and zinc sulfate), a salt
bridge or porous membrane, and a voltmeter. Assemble the electrochemical cell
by placing the electrodes in separate half-cells and connecting them through the
salt bridge.

2. Cell Construction: Prepare the half-cells by immersing each electrode in its

respective electrolyte solution. Ensure proper contact between the electrodes
and the solutions. The salt bridge should be filled with an electrolyte solution
that maintains electrical neutrality.

3. Measurement: Connect the electrodes to a voltmeter and measure the cell

potential. Record the initial voltage and monitor any changes over time. Ensure
that the voltmeter is correctly calibrated for accurate measurements.

4. Observations: Monitor the behaviour of the electrodes and electrolyte

solutions. Note any visible changes, such as gas evolution or color shifts.
Measure the current flow through the circuit and assess the stability of the
readings.

5. Data Analysis: Analyze the collected data to evaluate the performance of the
cell. Compare the observed values with theoretical predictions and identify any
discrepancies. Calculate the efficiency and effectiveness of the cell based on
the observed results.

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REACTIONS AND EQUATIONS:-

1. Galvanic Cell Reactions: In a copper-zinc galvanic cell, the overall reaction

can be represented as:

2. Electrolytic Cell Reactions: For the electrolysis of water, the reactions are:

3. Nernst Equation: The cell potential under non-standard conditions is given

by:

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CONCLUSION:-

Electrochemical cells represent a profound and versatile field of study within

chemistry, integrating principles of both chemical reactions and electrical engineering.
They are pivotal in understanding how chemical energy can be converted into
electrical energy and vice versa, which has significant implications for various
technological and industrial applications. This project has provided a comprehensive
exploration of electrochemical cells, examining their fundamental principles,
operational mechanisms, and practical uses.
The core of electrochemical cell functionality lies in the redox reactions that occur at
the electrodes. At the anode, oxidation reactions release electrons, which flow through
the external circuit to the cathode, where reduction reactions occur. This electron flow
is the basis of the electrical current produced by the cell. The efficiency and
effectiveness of an electrochemical cell depend significantly on the properties of the
electrodes and the electrolyte. Electrodes, typically made from metals or carbon-based
materials, must possess high electrical conductivity and stability to sustain the redox
reactions. The choice of electrolyte, which can be a liquid or a solid, is crucial as it
must facilitate the transport of ions between the electrodes while maintaining the cell’s
chemical balance.
One of the key theoretical aspects explored is the concept of cell potential, or
electromotive force (EMF), which determines the maximum voltage the cell can
produce. This potential is calculated based on the standard electrode potentials of the
half-reactions occurring at each electrode. The Nernst equation extends this
understanding by describing how the cell potential changes with varying
concentrations of reactants and products. This equation is essential for predicting the
behaviour of electrochemical cells under non-standard conditions, which is often the
case in practical applications.
Faraday’s laws of electrolysis offer further insight into the relationship between
electrical energy and chemical changes. Faraday’s first law states that the amount of
substance transformed at an electrode during electrolysis is directly proportional to the
amount of electric charge passed through the cell. The second law quantifies this by
relating the amount of substance to the electrochemical equivalent of the substance,
providing a quantitative measure of the electrochemical process. These laws are
foundational for understanding and optimizing processes such as electroplating, where
a metal is deposited onto a surface, and in industrial applications such as the
production of chemicals and materials.
Practical applications of electrochemical cells are extensive and diverse. In everyday
life, batteries are perhaps the most familiar example, serving as portable sources of
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electrical energy for a wide range of devices from mobile phones to electric vehicles.
The development of battery technology, including advances in lithium-ion and solid-
state batteries, highlights the importance of ongoing research and innovation in this
field. Each type of battery has its own advantages and limitations, which are dictated
by the materials used and the design of the electrochemical cell. For instance, lithium-
ion batteries offer high energy density and rechargeability, making them ideal for
portable electronics, while solid-state batteries promise greater safety and energy
density for future applications.
Electrochemical cells are also critical in environmental and industrial contexts. In
corrosion protection, for example, electrochemical cells are used in cathodic
protection systems to prevent metal degradation by making the metal the cathode in a
corrosion cell. Similarly, in water treatment, electrochemical cells can facilitate
processes such as electrolysis to produce chlorine and other chemicals that help in
disinfection and purification. These applications demonstrate the versatility of
electrochemical cells and their importance in addressing both practical and
environmental challenges.
Furthermore, the field of electrochemistry is continually evolving with advances in
materials science and nanotechnology. Researchers are exploring new materials for
electrodes and electrolytes to enhance cell performance, increase energy density, and
reduce costs. Innovations such as flexible and wearable batteries, as well as high-
capacity energy storage systems for renewable energy sources, are pushing the
boundaries of what is possible with electrochemical technology.
In conclusion, the study of electrochemical cells provides a deep understanding of the
interplay between chemical reactions and electrical energy. The principles governing
electrochemical cells—such as redox reactions, cell potential, and Faraday’s laws—
are not only fundamental to the field of electrochemistry but also essential for various
technological and industrial applications. The continued advancement in this field
promises to lead to new discoveries and improvements in energy storage,
environmental protection, and industrial processes. As technology progresses, the role
of electrochemical cells will likely become even more significant, highlighting their
enduring relevance and potential for future innovation. This project has underscored
the importance of electrochemical cells in both scientific research and practical
applications, reinforcing their critical role in shaping the future of technology and
industry.

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APPLICATION:-

Electrochemical cells are integral to numerous applications across various fields,

demonstrating their versatility and impact on modern technology and industry. Their
ability to convert chemical energy into electrical energy, and vice versa, underpins
many of the technological advancements and solutions we rely on today. This section
explores some of the key applications of electrochemical cells, including their role in
batteries, fuel cells, corrosion protection, and environmental technologies.
1. Batteries:
One of the most widespread applications of electrochemical cells is in battery
technology. Batteries, which are essentially portable electrochemical cells, store and
provide electrical energy for a multitude of devices. The basic principle involves two
electrodes (anode and cathode) separated by an electrolyte. The most common types
include alkaline, lead-acid, nickel-cadmium (NiCd), nickel-metal hydride (NiMH),
and lithium-ion (Li-ion) batteries. Each type has distinct characteristics tailored to
specific applications:
• Alkaline Batteries: Widely used in household items such as remote controls
and flashlights. They offer a good balance between capacity, cost, and shelf
life.
• Lead-Acid Batteries: Commonly used in automotive applications due to their
high current output and reliability. They are also used in backup power supplies
and large-scale energy storage systems.
• Nickel-Cadmium (NiCd) Batteries: Known for their robustness and ability to
deliver high discharge currents, they are used in power tools and emergency
lighting.
• Nickel-Metal Hydride (NiMH) Batteries: Offering higher capacity than NiCd
batteries and less environmental impact, they are used in rechargeable
household batteries and hybrid vehicles.
• Lithium-Ion (Li-ion) Batteries: With high energy density, long cycle life, and
low self-discharge rate, Li-ion batteries are critical in portable electronics such
as smartphones, laptops, and electric vehicles.
2. Fuel Cells:
Fuel cells are another important application of electrochemical cells. Unlike batteries,
which store electrical energy, fuel cells generate electricity through the continuous
chemical reaction of a fuel (such as hydrogen) with an oxidant (such as oxygen). This
process is highly efficient and produces minimal emissions. Various types of fuel cells
exist, including:

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 • Proton Exchange Membrane Fuel Cells (PEMFC): Known for their high
power density and quick start-up, PEMFCs are used in fuel cell vehicles and
portable power applications.
• Solid Oxide Fuel Cells (SOFC): Operating at high temperatures, SOFCs are
suitable for stationary power generation and can use a variety of fuels,
including natural gas.
• Alkaline Fuel Cells (AFC): Used in space missions due to their reliability and
efficiency, AFCs operate in alkaline solutions and have been employed in
NASA’s space shuttles.
3. Corrosion Protection:
Electrochemical cells play a crucial role in preventing and mitigating corrosion.
Corrosion, the degradation of metals due to electrochemical reactions with their
environment, can lead to significant damage and economic loss. One common method
of corrosion protection is cathodic protection, where the metal structure (such as
pipelines or ship hulls) is made the cathode in an electrochemical cell. This is
achieved through sacrificial anodes, which are more reactive than the protected metal
and corrode instead, or by impressed current systems, which use an external power
source to drive the protection current.
4. Environmental Technologies:
In environmental technology, electrochemical cells are used in water treatment and
pollution control. Electrochemical processes can treat wastewater by breaking down
pollutants into less harmful substances through oxidation or reduction reactions. For
example:
• Electrocoagulation: This process uses electric currents to remove suspended
particles and contaminants from water, making it suitable for treating industrial
effluents and municipal wastewater.
• Electrolytic Water Disinfection: Electrochemical cells generate chlorine or
ozone in situ to disinfect water, providing an efficient method for purifying
drinking water and treating wastewater.
• Electrochemical Sensors: Used for detecting pollutants and monitoring
environmental conditions, these sensors can measure gases like carbon dioxide
or nitrogen oxides, helping in environmental monitoring and regulatory
compliance.
5. Energy Storage and Conversion:
Electrochemical cells are pivotal in energy storage and conversion technologies. They
enable the storage of electrical energy in batteries and the conversion of chemical
energy into electrical energy in fuel cells. Advances in these technologies are crucial

15
for integrating renewable energy sources, such as solar and wind, into the power grid.
Energy storage solutions, like advanced batteries and supercapacitors, help balance
supply and demand, ensuring a stable and reliable energy system.
In summary, electrochemical cells are fundamental to a wide range of applications,
from everyday battery-powered devices to advanced technologies in energy storage
and environmental protection. Their ability to efficiently convert and store energy
makes them indispensable in modern technology, driving innovation and improving
our quality of life.

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BIBLIOGRAPHY:-

Books
1. "Electrochemical Cells and Energy Systems" by Daniel C. Truhlar
• Publisher: Cambridge University Press
• ISBN: 978-0521188890
• Cambridge University Press
2. "Principles of Electrochemistry" by Derek Pletcher and Frank C. Walsh
• Publisher: Wiley
• ISBN: 978-0470671144
• https://www.wiley.com/en-
us/Principles+of+Electrochemistry%2C+2nd+Edition-p-9780470671144
3. "Introduction to Modern Electrochemistry" by John O'M. Bockris and
Amulya K.N. Reddy
• Publisher: Springer
• ISBN: 978-0306470296
• https://link.springer.com/book/10.1007/978-1-4613-4182-5

Online Resources
1. Khan Academy - Electrochemical Cells
• https://www.khanacademy.org/science/chemistry/redox-
reactions/electrochemistry/v/electrochemical-cells
2. Chemguide - Electrochemical Cells
• Chemguide Electrochemical Cells
3. Royal Society of Chemistry - Electrochemical Cells
• RSC Electrochemical Cells
4. MIT OpenCourseWare - Electrochemical Cells
• MIT OCW Electrochemical Cells

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Government and Institutional Resources
1. National Renewable Energy Laboratory (NREL) - Fuel Cells and
Hydrogen
• NREL Fuel Cells
2. US Department of Energy - Energy Storage
• DOE Energy Storage
3. European Commission - Research on Electrochemical Cells
• https://ec.europa.eu/programmes/horizon2020/

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