ord count: 2989
W
Research Design:
esearch question: What is the effect on changingthe metal at the cathode: copper, nickel, lead, and
R
magnesium using their 1 mol dm3 sulfate solution for10 minutes, on the rate of electroplating by
measuring the change in mass (g) using Faraday’s Law for calculations?
This experiment was chosen due to the fact that many day to day items that are used are produced
through the process of electroplating. I always wondered what made ‘gold-plated’ jewelry so much more
expensive than jewelry that was found at department stores, and why it was still way cheaper than real
gold. I never understood the difference in the plated and non-plated items and the difference it made in the
longevity of the items. After researching and learning about electroplating, it is clear that due to the
electricity that goes into the plating of an inert item is immense and can be very costly. Even though pure
gold would only require 1.5-2.0V, it is still expensive to produce the electricity to cause the plating (“Bath
Plating (5000 ML Setup) Procedure Chart”).
I V:Different metals - copper, nickel, magnesium,zinc, lead (magnesium was 1cm thick whilst the others
were 2cm thick)
DV:Change in mass (g)
Background information:
lectroplating is extremely important and can be seen in our day to day lives, as many of the
E
items we use are produced through the process of electroplating (Williams). Electroplating is also known
as the process of metal coating that allows for the preservation of certain metals due to the coat around
them. This is seen in many jewelry that many know as ‘gold plated’. Even spoons are known to be plated
to prevent degradation and ensure safety when consuming food (Williams).
Nonetheless the process of electroplating requires sufficient electricity in order to plate the
selected item. The only requirement needed for the cathode to be plated accurately is for it to be inert.
This ensures that it does not react in the reaction whilst the ions are coming off from the metal at the
anode to replace the ions that are being plated onto the cathode. Therefore, this can also be seen as an
equilibrium reaction as both processes occur at the same time to ensure that the color of the solution does
not fade (Sharretts Plating Company).
The chosen metals for this internal assessment arecopper, nickel, magnesium, lead, and zinc.
They were chosen specifically due to their high reactivity but each one of them can be explored to further
justify their selection. Copper is a good choice for electroplating as it has high thermal conductivity
(ProPlate). Therefore copper is extremely versatile when it comes to electricity. Nickel is known to be one
of the optimal metals used for plating due to its ability to have high corrosion resistance (“Plating”).
In general, all of the metals were chosen as they deposit easily. Their ability to plate can be seen
from their reduction potentials as a higher reduction potential indicates that the ions have a greater ability
to be reduced and plated at the cathode, and opposite for lower reduction potentials (Wang et al.). From
this I can hypothesize that copper will have the greatest mass deposited and magnesium will have the
least mass deposited as corresponding to their reduction potentials.
Through this experiment, 5 different metals will be tested in their own sulfate solutions (1 mol
3
dm ) to ensure that they have optimal conditions forplating. Keeping the voltage and time constant, there
can be an analysis of which metal can be electroplated at the fastest possible rate by measuring the change
,in mass. Doing a calculation using faraday's second law to determine the mass of the metal that should be
deposited theoretically compared to the actual mass deposited (Rawal). The equation is stated below:
⋅𝑀
𝑄
𝑚 = 𝑛⋅𝐹
= mass of metal deposited (usually in grams)
m
n = number of electrons needed for the reduction to occur
F = Faraday’s constant (96,485C/mol)
Q = electric charge (in coulombs)
M = molar mass of metal (in g/mol)
owever the Q value is not a constant therefore it can be calculated from Faraday’s First Law below and
H
that value can be put back into the equation solving form. Faraday’s law is the amount of substance
produced during electrolysis directly proportional to the amount of electrical charge that flows through
the electrolyte (“About Faraday’s First Law”).
𝑄 = 𝐼⋅𝑡
I = current (in amperes)
t = time (in seconds)
Each metal can be observed and their half equations can be written to ensure that the gas they
produce is safe and will not be harmful to the environment or the experimenter.
Table 1:
Half equations for each metal to portray the possible gas released at the anode
Metals with their half equations to find gases released
Metals: Copper Zinc Magnesium Lead Nickel
Equations: eleases hydrogen
R Releases hydrogen gas eleases hydrogen
R eleases hydrogen
R eleases hydrogen
R
gas athode:
C gas gas gas
athode:
C Zn2+(aq)+2e-→
Zn(s) athode:
C athode:
C athode:
C
Cu2+(aq) +2e-→ Anode: Mg2+(aq)+2e-→
Mg Pb2+(aq)+2e-→
Pb Ni2+(aq)+2e-→Ni
Cu(s) Zn(s)→Zn2+(aq)+2e- (s) (s) (g)
Anode: Anode: Anode: Anode:
Cu(s) → Cu2+(aq) I f voltage is too Mg(s)→Mg2+(aq)+ Pb(s)→Pb2+(aq)+ Ni(s)→Ni2+(aq)+
+2e- high then gas can 2e- 2e- 2e-
If too acidic or be released: If the If voltage is too If the voltage is
voltage is too high 2H(aq)+2e-→H2(g) electroplating high then gas can too high then gas
then gas can be voltage is too high be released: can be released:
released: or solution is too 2H(aq)+2e-→H2 2H(aq)+2e-→H2
2H(aq)+2e-→H2( g) acidic: (g) (g)
2H(aq)+2e-→H2( g)
Methodology:
Controlled Variables What’s the Use & Purpose of it? How is it controlled
his time limit allows for sufficient time
T Start the stopwatch at zero and stop when
Time (10 min) for plating to show a significant change exactly when the alarm goes off.
in the mass (for both anode and cathode
, if measured).
his time limit allows for sufficient
T
plating without the overuse of electricity.
Justification - It is unsafe to keep the DC power supply on for too long as it can cause the temperature to
rise and cause oxidation of the solution instead of the plating occurring efficiently
his is used to produce a continuous
T Using the same DC power supply provided
Amperes (9V) current for the process of electroplating. by the lab technician.
J ustification - most of the solutions did not release harmful gas due to previously researching them
before experimenting (however with higher voltage oxidation of the solution could have occurred
releasing unknown products instead of the controlled hydrogen gas)
Re-suing the solution in between Using the constant concentration provided
Solution (1 mol dm ) 3 replicates allows for atom economy and by the lab technician.
prevents any waste of the solution and
oversuage of unnecessary solution.
Justification - the concentration of the solution is independent to the process of electroplating and does
need to be higher in order to efficiency produce data to answer my research question
Materials List:
- Lead electrode
1 - Lead sulfate (1 mol dm3) - 1Zinc electrode
- Zinc sulfate (1 mol dm3) - 1 Nickel electrode -Nickel sulfate (1 mol dm3)
- 1 Magnesium electrode - Magnesium sulfate (1 mol dm3) - 1 Copper electrode
- Copper sulfate (1 mol dm3) - masking tape - balance(+/-0.001)
- DC power supply (+/-0.50) - 150mL beaker (+/-0.05) - filtration paper
- Filtration pump
Procedure:
To prepare:
1. Sand the spoon that is being plated at the cathode for two minutes to remove the impurities
2. Then sand the metal that is being placed at the anode
3. Measure themassof the spoon
Experimenting:
1. 0.2g of Nickel Sulfate is dissolved in 120mL of the solution by using 150mL beaker to produce
concentration of 1 mol dm3
2. Place the spoon into the beaker and ensure that it is coated with the solution
3. Tape the spoon against the beaker to keep it in place
W
Research Design:
esearch question: What is the effect on changingthe metal at the cathode: copper, nickel, lead, and
R
magnesium using their 1 mol dm3 sulfate solution for10 minutes, on the rate of electroplating by
measuring the change in mass (g) using Faraday’s Law for calculations?
This experiment was chosen due to the fact that many day to day items that are used are produced
through the process of electroplating. I always wondered what made ‘gold-plated’ jewelry so much more
expensive than jewelry that was found at department stores, and why it was still way cheaper than real
gold. I never understood the difference in the plated and non-plated items and the difference it made in the
longevity of the items. After researching and learning about electroplating, it is clear that due to the
electricity that goes into the plating of an inert item is immense and can be very costly. Even though pure
gold would only require 1.5-2.0V, it is still expensive to produce the electricity to cause the plating (“Bath
Plating (5000 ML Setup) Procedure Chart”).
I V:Different metals - copper, nickel, magnesium,zinc, lead (magnesium was 1cm thick whilst the others
were 2cm thick)
DV:Change in mass (g)
Background information:
lectroplating is extremely important and can be seen in our day to day lives, as many of the
E
items we use are produced through the process of electroplating (Williams). Electroplating is also known
as the process of metal coating that allows for the preservation of certain metals due to the coat around
them. This is seen in many jewelry that many know as ‘gold plated’. Even spoons are known to be plated
to prevent degradation and ensure safety when consuming food (Williams).
Nonetheless the process of electroplating requires sufficient electricity in order to plate the
selected item. The only requirement needed for the cathode to be plated accurately is for it to be inert.
This ensures that it does not react in the reaction whilst the ions are coming off from the metal at the
anode to replace the ions that are being plated onto the cathode. Therefore, this can also be seen as an
equilibrium reaction as both processes occur at the same time to ensure that the color of the solution does
not fade (Sharretts Plating Company).
The chosen metals for this internal assessment arecopper, nickel, magnesium, lead, and zinc.
They were chosen specifically due to their high reactivity but each one of them can be explored to further
justify their selection. Copper is a good choice for electroplating as it has high thermal conductivity
(ProPlate). Therefore copper is extremely versatile when it comes to electricity. Nickel is known to be one
of the optimal metals used for plating due to its ability to have high corrosion resistance (“Plating”).
In general, all of the metals were chosen as they deposit easily. Their ability to plate can be seen
from their reduction potentials as a higher reduction potential indicates that the ions have a greater ability
to be reduced and plated at the cathode, and opposite for lower reduction potentials (Wang et al.). From
this I can hypothesize that copper will have the greatest mass deposited and magnesium will have the
least mass deposited as corresponding to their reduction potentials.
Through this experiment, 5 different metals will be tested in their own sulfate solutions (1 mol
3
dm ) to ensure that they have optimal conditions forplating. Keeping the voltage and time constant, there
can be an analysis of which metal can be electroplated at the fastest possible rate by measuring the change
,in mass. Doing a calculation using faraday's second law to determine the mass of the metal that should be
deposited theoretically compared to the actual mass deposited (Rawal). The equation is stated below:
⋅𝑀
𝑄
𝑚 = 𝑛⋅𝐹
= mass of metal deposited (usually in grams)
m
n = number of electrons needed for the reduction to occur
F = Faraday’s constant (96,485C/mol)
Q = electric charge (in coulombs)
M = molar mass of metal (in g/mol)
owever the Q value is not a constant therefore it can be calculated from Faraday’s First Law below and
H
that value can be put back into the equation solving form. Faraday’s law is the amount of substance
produced during electrolysis directly proportional to the amount of electrical charge that flows through
the electrolyte (“About Faraday’s First Law”).
𝑄 = 𝐼⋅𝑡
I = current (in amperes)
t = time (in seconds)
Each metal can be observed and their half equations can be written to ensure that the gas they
produce is safe and will not be harmful to the environment or the experimenter.
Table 1:
Half equations for each metal to portray the possible gas released at the anode
Metals with their half equations to find gases released
Metals: Copper Zinc Magnesium Lead Nickel
Equations: eleases hydrogen
R Releases hydrogen gas eleases hydrogen
R eleases hydrogen
R eleases hydrogen
R
gas athode:
C gas gas gas
athode:
C Zn2+(aq)+2e-→
Zn(s) athode:
C athode:
C athode:
C
Cu2+(aq) +2e-→ Anode: Mg2+(aq)+2e-→
Mg Pb2+(aq)+2e-→
Pb Ni2+(aq)+2e-→Ni
Cu(s) Zn(s)→Zn2+(aq)+2e- (s) (s) (g)
Anode: Anode: Anode: Anode:
Cu(s) → Cu2+(aq) I f voltage is too Mg(s)→Mg2+(aq)+ Pb(s)→Pb2+(aq)+ Ni(s)→Ni2+(aq)+
+2e- high then gas can 2e- 2e- 2e-
If too acidic or be released: If the If voltage is too If the voltage is
voltage is too high 2H(aq)+2e-→H2(g) electroplating high then gas can too high then gas
then gas can be voltage is too high be released: can be released:
released: or solution is too 2H(aq)+2e-→H2 2H(aq)+2e-→H2
2H(aq)+2e-→H2( g) acidic: (g) (g)
2H(aq)+2e-→H2( g)
Methodology:
Controlled Variables What’s the Use & Purpose of it? How is it controlled
his time limit allows for sufficient time
T Start the stopwatch at zero and stop when
Time (10 min) for plating to show a significant change exactly when the alarm goes off.
in the mass (for both anode and cathode
, if measured).
his time limit allows for sufficient
T
plating without the overuse of electricity.
Justification - It is unsafe to keep the DC power supply on for too long as it can cause the temperature to
rise and cause oxidation of the solution instead of the plating occurring efficiently
his is used to produce a continuous
T Using the same DC power supply provided
Amperes (9V) current for the process of electroplating. by the lab technician.
J ustification - most of the solutions did not release harmful gas due to previously researching them
before experimenting (however with higher voltage oxidation of the solution could have occurred
releasing unknown products instead of the controlled hydrogen gas)
Re-suing the solution in between Using the constant concentration provided
Solution (1 mol dm ) 3 replicates allows for atom economy and by the lab technician.
prevents any waste of the solution and
oversuage of unnecessary solution.
Justification - the concentration of the solution is independent to the process of electroplating and does
need to be higher in order to efficiency produce data to answer my research question
Materials List:
- Lead electrode
1 - Lead sulfate (1 mol dm3) - 1Zinc electrode
- Zinc sulfate (1 mol dm3) - 1 Nickel electrode -Nickel sulfate (1 mol dm3)
- 1 Magnesium electrode - Magnesium sulfate (1 mol dm3) - 1 Copper electrode
- Copper sulfate (1 mol dm3) - masking tape - balance(+/-0.001)
- DC power supply (+/-0.50) - 150mL beaker (+/-0.05) - filtration paper
- Filtration pump
Procedure:
To prepare:
1. Sand the spoon that is being plated at the cathode for two minutes to remove the impurities
2. Then sand the metal that is being placed at the anode
3. Measure themassof the spoon
Experimenting:
1. 0.2g of Nickel Sulfate is dissolved in 120mL of the solution by using 150mL beaker to produce
concentration of 1 mol dm3
2. Place the spoon into the beaker and ensure that it is coated with the solution
3. Tape the spoon against the beaker to keep it in place
