Thien-An Le
Supervisor: Dr. Bergen
LOGBOOK FOR SCIENTIFIC
INVESTIGATION
Yr 12 Chemistry Unit 3 and 4 (2025)
,Table of Contents
Contents
Table of Contents....................................................................................................................1
Introduction and Preface.........................................................................................................2
Deciding on the topic...............................................................................................................3
Experiment Design..................................................................................................................4
Background Research............................................................................................................12
Research Topic......................................................................................................................17
Experiment............................................................................................................................19
Results and Observations:.....................................................................................................22
Discussion............................................................................................................................26
Summary/Analysis of Results.............................................................................................26
Potential Extraneous Variables and Limitations in Method..................................................28
Further Research...............................................................................................................29
Conclusion............................................................................................................................30
Acknowledgements...............................................................................................................31
1|P a g e
,Introduction and Preface
25/05/2025
The purpose of this logbook is to provide a basis for further learning in future studies. This
logbook will include my planning, thinking process, observations, data, research, and
conclusions.
The goal of my experiment is to formulate a scientific investigation that relates to the content
covered in VCE Chemistry Units 3 & 4. My partners (Nethaya and Hanah) and I will conduct the
experiment at our school, Christway College, and the formation of my research and results will
be done both at school and at home.
This experiment aims to investigate the effect of electrolyte concentration, specifically the
cathode electrolyte concentration on the voltage produced by a galvanic cell. Voltage (or
potential difference) is the difference in electric potential between two points in a circuit 1. A
galvanic cell is a type of electrochemical cell in which chemical energy is converted into
electrical energy.2 To calculate the voltage of a galvanic cell in standard conditions (25 degrees
and 1M), the following equation can be used: E° cell = E° cathode - E° anode. This will measure
the difference in the standard electrode potential of two points in the circuit (each half-cell)
Furthermore, the voltage of a galvanic cell can also be calculated by using a voltmeter.
In the following experiment, the galvanic cell that is being investigated is the Daniell Cell, which
involves a copper half-cell and a zinc half-cell. For this investigation, the reaction is
spontaneous, and at the copper half-cell, reduction occurs, meaning it is the cathode. In
comparison, at the zinc half-cell, oxidation occurs, meaning it is the anode. Electrons are
pushed from the zinc half-cell to the copper half-cell, which causes there to be a voltage.
Furthermore, this investigation also used the Nernst equation to predict the voltages that will
be produced when the CuSO₄ concentration is changed. The Nernst equation allows for the
determination of the cell potential (voltage) under non-standard conditions.
o 0.0592 V
The Nernst equation is: E=E − log10 Q
n
This investigation looked at the effect of the CuSO₄ electrolyte concentration on the voltage of
the Daniell cell. When the concentration of the CuSO₄ is lower, the number of ions available to
be reduced is lower, and thus there is a lower pull of electrons to the copper half-cell, therefore
the voltage produced is lower. In comparison, when the CuSO₄ concentration is higher, there
are more ions available to accept electrons, and therefore there is a greater pull of electrons
from the zinc half-cell to the copper half-cell, resulting in a higher voltage.
1
https://www.allaboutcircuits.com/textbook/direct-current/chpt-1/voltage-current/
2
Heinemann Textbook Chapter 5.1
2|P a g e
, Deciding on the topic
19/05/2025
Today, we decided on our topic. We wanted to do something relating to galvanic cells or
electrolysis. We brainstormed a couple of ideas of things we could investigate such as:
- The effect of varying electrolyte concentration
- The effect of different type of electrode
- The effect of different surface areas of electrode
- The effect of temperature on the cell
As a group we decided that we wanted to investigate galvanic cells, since it was a type of cell
that we understood well and could easily investigate how different variables affected it. From
all of the ideas we brainstormed, we found that the effect of varying concentration of electrolyte
was the easiest to manipulate and most time efficient to conduct.
We also had to discuss what was our end point of the experiment and what we were measuring.
We decided to measure the voltage that the cell produced, and thus that would be our end
point. We could measure the voltage using a voltmeter.
Before continuing with our investigation, we did a bit of research about varying concentrations
of electrolyte on galvanic cells and found a similar experiment that someone conduced with
carrying concentrations of electrolyte.3 This experiment however, had two different variables
they tested. They tested the effect of temperature as well as the effect of concentration. In this
experiment, they found that higher temperatures resulted in a higher voltage, and lower
electrolyte concentrations resulted in a lower voltage. This experiment gave as an idea of what
concentration of electrolyte could do to the voltage of our cell.
We also wanted to run our idea with Dr. Bergen and see if there were other effects we could
investigate for galvanic cells. After talking about our idea with Dr. Bergen, he said that it was a
simple investigation and recommended us to do it.
At the end of the class, we finalize our topic which is: a galvanic cell with varying concentration
of electrolyte to see how it would affect the voltage that the cell produced.
-
3
https://pennyroyalresearch.wordpress.com/wp-content/uploads/2017/01/the-effect-of-
temperature-and-concentration-on-galvanic-cells.pdf
3|P a g e
Supervisor: Dr. Bergen
LOGBOOK FOR SCIENTIFIC
INVESTIGATION
Yr 12 Chemistry Unit 3 and 4 (2025)
,Table of Contents
Contents
Table of Contents....................................................................................................................1
Introduction and Preface.........................................................................................................2
Deciding on the topic...............................................................................................................3
Experiment Design..................................................................................................................4
Background Research............................................................................................................12
Research Topic......................................................................................................................17
Experiment............................................................................................................................19
Results and Observations:.....................................................................................................22
Discussion............................................................................................................................26
Summary/Analysis of Results.............................................................................................26
Potential Extraneous Variables and Limitations in Method..................................................28
Further Research...............................................................................................................29
Conclusion............................................................................................................................30
Acknowledgements...............................................................................................................31
1|P a g e
,Introduction and Preface
25/05/2025
The purpose of this logbook is to provide a basis for further learning in future studies. This
logbook will include my planning, thinking process, observations, data, research, and
conclusions.
The goal of my experiment is to formulate a scientific investigation that relates to the content
covered in VCE Chemistry Units 3 & 4. My partners (Nethaya and Hanah) and I will conduct the
experiment at our school, Christway College, and the formation of my research and results will
be done both at school and at home.
This experiment aims to investigate the effect of electrolyte concentration, specifically the
cathode electrolyte concentration on the voltage produced by a galvanic cell. Voltage (or
potential difference) is the difference in electric potential between two points in a circuit 1. A
galvanic cell is a type of electrochemical cell in which chemical energy is converted into
electrical energy.2 To calculate the voltage of a galvanic cell in standard conditions (25 degrees
and 1M), the following equation can be used: E° cell = E° cathode - E° anode. This will measure
the difference in the standard electrode potential of two points in the circuit (each half-cell)
Furthermore, the voltage of a galvanic cell can also be calculated by using a voltmeter.
In the following experiment, the galvanic cell that is being investigated is the Daniell Cell, which
involves a copper half-cell and a zinc half-cell. For this investigation, the reaction is
spontaneous, and at the copper half-cell, reduction occurs, meaning it is the cathode. In
comparison, at the zinc half-cell, oxidation occurs, meaning it is the anode. Electrons are
pushed from the zinc half-cell to the copper half-cell, which causes there to be a voltage.
Furthermore, this investigation also used the Nernst equation to predict the voltages that will
be produced when the CuSO₄ concentration is changed. The Nernst equation allows for the
determination of the cell potential (voltage) under non-standard conditions.
o 0.0592 V
The Nernst equation is: E=E − log10 Q
n
This investigation looked at the effect of the CuSO₄ electrolyte concentration on the voltage of
the Daniell cell. When the concentration of the CuSO₄ is lower, the number of ions available to
be reduced is lower, and thus there is a lower pull of electrons to the copper half-cell, therefore
the voltage produced is lower. In comparison, when the CuSO₄ concentration is higher, there
are more ions available to accept electrons, and therefore there is a greater pull of electrons
from the zinc half-cell to the copper half-cell, resulting in a higher voltage.
1
https://www.allaboutcircuits.com/textbook/direct-current/chpt-1/voltage-current/
2
Heinemann Textbook Chapter 5.1
2|P a g e
, Deciding on the topic
19/05/2025
Today, we decided on our topic. We wanted to do something relating to galvanic cells or
electrolysis. We brainstormed a couple of ideas of things we could investigate such as:
- The effect of varying electrolyte concentration
- The effect of different type of electrode
- The effect of different surface areas of electrode
- The effect of temperature on the cell
As a group we decided that we wanted to investigate galvanic cells, since it was a type of cell
that we understood well and could easily investigate how different variables affected it. From
all of the ideas we brainstormed, we found that the effect of varying concentration of electrolyte
was the easiest to manipulate and most time efficient to conduct.
We also had to discuss what was our end point of the experiment and what we were measuring.
We decided to measure the voltage that the cell produced, and thus that would be our end
point. We could measure the voltage using a voltmeter.
Before continuing with our investigation, we did a bit of research about varying concentrations
of electrolyte on galvanic cells and found a similar experiment that someone conduced with
carrying concentrations of electrolyte.3 This experiment however, had two different variables
they tested. They tested the effect of temperature as well as the effect of concentration. In this
experiment, they found that higher temperatures resulted in a higher voltage, and lower
electrolyte concentrations resulted in a lower voltage. This experiment gave as an idea of what
concentration of electrolyte could do to the voltage of our cell.
We also wanted to run our idea with Dr. Bergen and see if there were other effects we could
investigate for galvanic cells. After talking about our idea with Dr. Bergen, he said that it was a
simple investigation and recommended us to do it.
At the end of the class, we finalize our topic which is: a galvanic cell with varying concentration
of electrolyte to see how it would affect the voltage that the cell produced.
-
3
https://pennyroyalresearch.wordpress.com/wp-content/uploads/2017/01/the-effect-of-
temperature-and-concentration-on-galvanic-cells.pdf
3|P a g e
