Unit 6
Part B: investigation project.
Timeline of tasks needed for the experiment.
Date of the task. What I have done on this day.
28th April 2023. On this day, I am going to be researching about my practical and my chosen area of study to see what I
am going to need to carry out my own practical. This day would be full of researching about the diffusion
practical and what I am going to need to successfully carry it out.
29th April 2023. On this day I am going to get some agar jelly powder, which can be brought from a shop, so that I can
start to make my agar jelly. I will know how to make my agar jelly for the practical as I have researched
about it on the previous day.
30th April 2023. On this day I am going to make my agar jelly and leave it to set in an incubator overnight. I am going to
make multiple sets of agar jelly so that if one batch fails, I still have jelly to use. I would also put one agar
jelly batch in the fridge, so that it hardens and is ready to use for the experiment.
1st May 2023. On this day, I am going to check on the agar jelly to see if it has set, and I am going to get the equipment
that I need for the experiment ready so that I know I have everything to conduct the practical.
2nd may 2023. On this day, I am going to get the equipment ready, and get the agar jelly ready for the practical this
would be the final day to get everything that I need ready and to buy the things that I don’t have so that
I can successfully carry out the practical.
3rd may 2023. This is the day that I am going to carry out my experiment and see how the increase in surface area
affects the rate of diffusion on agar jelly.
Variables.
Independent variable.
My independent variable is changing the surface area of the agar jelly cubes. This is
from the range of 5×5×5cm to 10×10×10cm to 15×15×15cm cube sizes. I am going to
achieve these sizes by using a 30cm ruler and a scalpel to cut the cubes, so that they
can accurately get cut to size, and the cubes are in cm 3.
Dependent variable.
I am going to be measuring the time taken for the agar jelly cubes to change colour from pink to
colourless. This is going to be done by using a stopwatch and starting the stopwatch once the agar
jelly cubes have entered the beaker and stopping the watch, when the cubes have colour changed. I
am going to be measuring the rate of diffusion in seconds.
Control variables.
Control variable Why does it have to be controlled? How is it going to be controlled?
0.1M HCL. If I don’t have the same concentration of HCL in each I am going to measure out 0.1M of HCL at eye
beaker, then the results would be incorrect. This is level with an appropriate sized beaker, so that I
because concentration is a factor that affects diffusion, would be accurate when pouring and measuring
and the practical that I do would be wrong. out the acid.
The same beakers Using the same equipment to measure out the water After using the beaker to measure out what I
and the acid is better than changing the equipment. need, I would rinse the beaker out to use again.
The temperature Temperature is a factor that affects diffusion. If one I would make sure that the HCL has a room
of the HCL. beaker has HCL that is a higher temperature, then temperature and I would do this by using a
diffusion would happen faster, altering the results, thermometer to keep the temperature the
making the practical less accurate. same.
1
, Aim.
The aim of this investigation is to see how the rate of diffusion changes when the surface area of the
agar jelly increases from 5×5×5cm to 10×10×10cm to 15×15×15cm.
Hypothesis.
As the surface area of the agar jelly cubes increase from 5×5×5cm to 10×10×10cm to 15×15×15cm,
the rate of diffusion would also increase, as the time taken for the colour of the agar jelly cubes to
change colour would be longer. This is because when there is a greater surface area, the particles
have more space to diffuse across, increasing the rate of diffusion.
Equipment needed.
1. Gloves. Gloves are available in a lab and they are going to be used to protect my hands from
any irritant during the experiment
2. Goggles. Goggles are available in a lab and they are going to be used to protect my eyes
from any chemical that can irritate them
3. Agar powder. The agar powder isn’t available from a lab but they can be brought from a
shop. The powder is going to be used for making the agar jelly so
that it can be cut into cubes to carry out the practical
4. Weighing scales. The weighing scales can be found in a lab and it
is going to be used to measure out the agar jelly powder to make
the agar solution
5. A calculator. The calculator is going to be used for calculating an
average result after all the results have been collected and it can
be found in a lab
6. An incubator. The incubator can be found in a lab and it is going
to be used to set the agar jelly solution to turn it into solid cubes
7. A spoon. A spoon can be found in a lab, and it is going to be used to mix the agar jelly
solution
8. A bowl. A bowl can be found in a lab and it is going to be used to mix the agar jelly powder
into a solution
9. Water. You can get water from the Lab sink and water is going to be used to make the agar
jelly solution
10. 100ml beaker. This Beaker can be found in a lab and it is going to be used to measure out
100ml of water. The uncertainty level of a beaker is 0.5% to 1%.
11. Phenolphthalein indicator. Phenolphthalein indicator can be found in a lab and it is going to
be used to make the agar jelly solution pink
12. A 5ml pipette to add the phenolphthalein indicator. A pipette can be found in the lab and it
is going to be used to add the indicator into the agar jelly solution. The uncertainty level for
a pipette is +0.0mL
13. 1M of sodium hydroxide (NaOH). Sodium hydroxide can be found in a lab and it is going to
be used to make the agar jelly
14. Agar jelly mould. An agar jelly mould can be found in a lab but most likely you would have to
buy a mould the mould is going to be used to shape the agar jelly into cubes
15. Scalpel. The scalpel can be round in a lab but if not, you can easily buy one. It is going to be
used to cut the agar jelly cubes to the preferred sizes that I need for the experiment
16. 30cm ruler. A ruler can be found in a lab and it is going to be used to measure the cubes to
the sizes that I want. The uncertainty level for a 30cm ruler is 0.5mm.
2
Part B: investigation project.
Timeline of tasks needed for the experiment.
Date of the task. What I have done on this day.
28th April 2023. On this day, I am going to be researching about my practical and my chosen area of study to see what I
am going to need to carry out my own practical. This day would be full of researching about the diffusion
practical and what I am going to need to successfully carry it out.
29th April 2023. On this day I am going to get some agar jelly powder, which can be brought from a shop, so that I can
start to make my agar jelly. I will know how to make my agar jelly for the practical as I have researched
about it on the previous day.
30th April 2023. On this day I am going to make my agar jelly and leave it to set in an incubator overnight. I am going to
make multiple sets of agar jelly so that if one batch fails, I still have jelly to use. I would also put one agar
jelly batch in the fridge, so that it hardens and is ready to use for the experiment.
1st May 2023. On this day, I am going to check on the agar jelly to see if it has set, and I am going to get the equipment
that I need for the experiment ready so that I know I have everything to conduct the practical.
2nd may 2023. On this day, I am going to get the equipment ready, and get the agar jelly ready for the practical this
would be the final day to get everything that I need ready and to buy the things that I don’t have so that
I can successfully carry out the practical.
3rd may 2023. This is the day that I am going to carry out my experiment and see how the increase in surface area
affects the rate of diffusion on agar jelly.
Variables.
Independent variable.
My independent variable is changing the surface area of the agar jelly cubes. This is
from the range of 5×5×5cm to 10×10×10cm to 15×15×15cm cube sizes. I am going to
achieve these sizes by using a 30cm ruler and a scalpel to cut the cubes, so that they
can accurately get cut to size, and the cubes are in cm 3.
Dependent variable.
I am going to be measuring the time taken for the agar jelly cubes to change colour from pink to
colourless. This is going to be done by using a stopwatch and starting the stopwatch once the agar
jelly cubes have entered the beaker and stopping the watch, when the cubes have colour changed. I
am going to be measuring the rate of diffusion in seconds.
Control variables.
Control variable Why does it have to be controlled? How is it going to be controlled?
0.1M HCL. If I don’t have the same concentration of HCL in each I am going to measure out 0.1M of HCL at eye
beaker, then the results would be incorrect. This is level with an appropriate sized beaker, so that I
because concentration is a factor that affects diffusion, would be accurate when pouring and measuring
and the practical that I do would be wrong. out the acid.
The same beakers Using the same equipment to measure out the water After using the beaker to measure out what I
and the acid is better than changing the equipment. need, I would rinse the beaker out to use again.
The temperature Temperature is a factor that affects diffusion. If one I would make sure that the HCL has a room
of the HCL. beaker has HCL that is a higher temperature, then temperature and I would do this by using a
diffusion would happen faster, altering the results, thermometer to keep the temperature the
making the practical less accurate. same.
1
, Aim.
The aim of this investigation is to see how the rate of diffusion changes when the surface area of the
agar jelly increases from 5×5×5cm to 10×10×10cm to 15×15×15cm.
Hypothesis.
As the surface area of the agar jelly cubes increase from 5×5×5cm to 10×10×10cm to 15×15×15cm,
the rate of diffusion would also increase, as the time taken for the colour of the agar jelly cubes to
change colour would be longer. This is because when there is a greater surface area, the particles
have more space to diffuse across, increasing the rate of diffusion.
Equipment needed.
1. Gloves. Gloves are available in a lab and they are going to be used to protect my hands from
any irritant during the experiment
2. Goggles. Goggles are available in a lab and they are going to be used to protect my eyes
from any chemical that can irritate them
3. Agar powder. The agar powder isn’t available from a lab but they can be brought from a
shop. The powder is going to be used for making the agar jelly so
that it can be cut into cubes to carry out the practical
4. Weighing scales. The weighing scales can be found in a lab and it
is going to be used to measure out the agar jelly powder to make
the agar solution
5. A calculator. The calculator is going to be used for calculating an
average result after all the results have been collected and it can
be found in a lab
6. An incubator. The incubator can be found in a lab and it is going
to be used to set the agar jelly solution to turn it into solid cubes
7. A spoon. A spoon can be found in a lab, and it is going to be used to mix the agar jelly
solution
8. A bowl. A bowl can be found in a lab and it is going to be used to mix the agar jelly powder
into a solution
9. Water. You can get water from the Lab sink and water is going to be used to make the agar
jelly solution
10. 100ml beaker. This Beaker can be found in a lab and it is going to be used to measure out
100ml of water. The uncertainty level of a beaker is 0.5% to 1%.
11. Phenolphthalein indicator. Phenolphthalein indicator can be found in a lab and it is going to
be used to make the agar jelly solution pink
12. A 5ml pipette to add the phenolphthalein indicator. A pipette can be found in the lab and it
is going to be used to add the indicator into the agar jelly solution. The uncertainty level for
a pipette is +0.0mL
13. 1M of sodium hydroxide (NaOH). Sodium hydroxide can be found in a lab and it is going to
be used to make the agar jelly
14. Agar jelly mould. An agar jelly mould can be found in a lab but most likely you would have to
buy a mould the mould is going to be used to shape the agar jelly into cubes
15. Scalpel. The scalpel can be round in a lab but if not, you can easily buy one. It is going to be
used to cut the agar jelly cubes to the preferred sizes that I need for the experiment
16. 30cm ruler. A ruler can be found in a lab and it is going to be used to measure the cubes to
the sizes that I want. The uncertainty level for a 30cm ruler is 0.5mm.
2
