Blue Fire Pointer S207 ISS Investigating the factor that affect electrolysis of saltwater and calcium carbonate: 2. Methods

2. Methods

2. Methods

To analyse our results, we have to first measure the mass of all the anodes and cathodes at before starting the experiment. After running the experiment for ½ hour, dry the anodes and cathodes thoroughly for 1 hour and measure the mass using a electronic mass balance.Repeat each experiment again and take the average mass. Next we have record everything in a table and find out the difference in mass of the anodes and cathodes before and after the experiment.
We are going to focus mainly on the mass difference of cathodes as mass difference tells us the mass of calcium carbonate deposited on the cathodes, which leads us to the conclusion.

2.1 Equipment List
  • Electrical cable resistors (3 sets)
  • Anode made of Copper, Aluminium and Brass (1m tube for each)
  • Cathode made of Iron mesh (3 big sheets)
  • Hydrochloric acid (0.5 mol/litre)
  • Calcium Carbonate (dead corals) (2 big packets of 1kg each)
  • Chiller (1)
  • 3 transparent bins (1250 ml x 3)
  • 1 large tank
  • Temperature sensor (3)
  • Sea Salt ( 1 Bucket )
  • Salinity sensor with data logger (1)
  • Gloves (4 sets)
  • Water pump (1)
  • Metal cutter (1)
  • Tripod stand (3 of them)
  • Crocodile clips (20 sets)










Gloves, anode, cathode
















The Chiller
Sea Salt
Calcium Carbonate

Water pump














Tube






















Salinity Sensor 2.2 Diagrams of experimental setup



Figure 1: Sketch of setup for experiment 1

Figure 2: Experimental setup used to test, find out which temperature results in the highest rate of electrolysis.




2.3 Procedures
For experiment on the anode that affect the rate of electrolysis.
Step 1:
We will cut the each piece of iron mesh into 9 smaller equal pieces. We will then cut the corners of each of the smaller iron mesh so we can fold it into a dome shape.
Step 2:
We will then use a pipe cutter to cut out one small piece of each of the 3 pipes. This will be used as the anode for each of the circuits.
Step 3:

We will then submerge 3 small dome shape iron mesh and one of each small pipe piece into hydrochloric acid to remove the galvanise layer of the metals as they may not react if we did not do so. This is because the galvanise layer prevent the metals from rusting.
Step 4:
After 3 minutes, we will take the 3 small dome shape iron mesh out of the hydrochloric acid and put it into a pail with deionized water to wash away the hydrochloric acid and the remaining bits of galvanise layer.
Step 5:
We will then measure the mass of each of the small dome shape iron mesh and anode and we will then pair each small dome shape iron mesh to one type of the anode.
Step 6:
We will pour 150 grams of calcium carbonate into each bin so as to represent the dead corals in the sea. We will then pour 1 liter of tap water into each of the 3 bins we are using and pour another 35 grams of red sea salt into each of the bins so that the solution would be approximately that of seawater.

Step 7:
We will connect the crocodile clips accordingly to the anode and the 3 small dome shape iron mesh (The Anode connected to the positive terminal and the Cathode connected to the negative terminal of the adapter) and lower each pair into each of the 3 pails.
Step 8:
We will then on the power source to let calcium carbonate form on each small dome shape iron mesh in the 3 bins. Electrolysis will be directly proportional to the calcium carbonate forming on each dome shape iron mesh so we will be able to tell which anode is able to increase the rate of electrolysis by getting the mass difference of the small dome shape iron mesh and/or anode for the start and the end of the experiment.
Step 9:
We will off the power source after ½  an hour and take out the anode and small dome shape iron mesh of each bin. We will then dry it for approximately 1h before measuring the mass of each of the anode and small dome shape iron mesh and getting the difference.


Step 10:
We will then repeat the experiment a second time to get the average of the result as that will allow the results to be more accurate.

For experiment on the temperature that affect the rate of electrolysis
Step 1:
We will cut the each piece of iron mesh into 9 smaller equal pieces. We will then cut the corners of each of the smaller iron mesh so we can fold it into a dome shape.
Step 2:
We will then use a pipe cutter to cut out one small piece of the brass pipe. This will be used as the anode for the circuit.
Step 3:
We will then submerge the dome shape iron mesh and the anode into hydrochloric acid to remove the galvanise layer of the metals as they may not react if we did not do so. This is because the galvanise layer prevent the metals from rusting.
Step 4:
After 3 minutes, we will take the small dome shape iron mesh and anode out of the hydrochloric acid and put it into a pail with deionized water to wash away the hydrochloric acid and the remaining bits of galvanise layer.
Step 5:
We will then measure the mass of the small dome shape iron mesh and anode.
Step 6:
We will pour 3750 grams of calcium carbonate(To represent the calcium carbonate), 25 liter of tap and 875 grams of red sea salt into a big fish tank so that the solution would be approximately that of seawater.
Step 7:
We will then connect the chiller to the power source and set it to chill the water to 25 ˚C.
Step 8:
We will connect the crocodile clips accordingly to the anode and the small dome shape iron mesh (The Anode connected to the positive terminal and the Cathode connected to the negative terminal of the adapter) and lower the pair into the big fish tank.
Step 9:
We will then on the power source to let calcium carbonate form on the small dome shape iron mesh in the big fish tank. Electrolysis will be directly proportion to the calcium carbonate forming on the dome shape iron mesh so we will be able to tell which temperature is able to increase the rate of electrolysis by getting the mass difference of the small dome shape iron mesh and/or anode for the start and the end of the experiment.
Step 10:
We will off the power source after ½  an hour and take out the anode and small dome shape iron mesh in the large fish tank. We will then dry it for approximately 1h before measuring the mass of the anode and small dome shape iron mesh and getting the difference.
Step 11:
We will then repeat the experiment a second time to get the average of the result as that will allow the results to be more accurate.
Step 12:
We will then change the chiller temperature for “Step 6” to 20˚C followed by 15˚C . We will then be able to compare the results of the different small dome shape iron mesh and anode.









































2.4 Risk Assessment and Management  


Risk
Management
Electrocution
Use batteries instead of direct power supply.
Corals might die if the temperature is not kept constant
Ensure that the chiller is functioning properly. A temperature sensor can be placed to monitor the temperature and to check if the chiller is functioning properly.
Corals may take a long time to grow
Increase the voltage of the adapter, but not too high that it will kill the corals
The type of corals that we buy cannot grow on the cathode
Do research on what kind of corals that can grow on the cathode easily.
The shape of the cathode might not be suitable for the corals to grow.
The shape of the cathode can be a dome shape and thus corals can grow underneath it as well.
The wire attached to the cathode will rust/corrode when submerged in the water and thus electricity will not be able to flow through.
Crocodile clip is waterproof and thus when submerged, the wire will not get soaked in the water.
People may burn their hand if they place their hand in hydrochloric acid
We will use a tong to take out the cathode and anodes.










2.5 Data Analysis

To analyse our results, first, we have to measure the mass (in grams) for all the anodes and cathodes of the different set ups before starting the experiment. After running the experiment for ½ hour, we dried the anodes and cathodes thoroughly (ensuring that the substances found on the anode and cathode after the experiment remains the same) and measure the mass (in grams) using an electronic mass balance.

Next, repeat each experiment again and take the average mass. Next we have record everything in a table and find out the difference in mass of the anodes and cathodes before and after the experiment. We are also going to put the results in a graph form so that it will be easier to see the difference in mass.

We are going to focus mainly on the mass difference of cathodes before and after the experiment. This is because, the mass difference tells us the mass of calcium carbonate deposited on the cathodes, which leads us to the conclusion of the results. The mass difference of the anodes is not important, but we are collecting it to make sure our experiment is a fair experiment. This is to also ensure that our results are accurate and precise.

The cathode with the most anode difference shows that the process, electrolysis took place at a greater rate in that particular experimental set up when compared to the rest. Thus, we can conclude that the particular factor is the most suitable for the process, electrolysis.


2.5.1 At first this was how we plan to put our results.


Measurements of the dependent variable

Independent Variable
Reading 1
Reading 2
Average Reading
Remarks
1 Copper




2 Aluminium




3 Brass




Table 1: Results for Experiment Table of the different types of anodes used against the rate of electrolysis



Measurements of the dependent variable

Independent Variable (Temperature)
Reading 1
Reading 2
Average Reading
Remarks
115˚C




2 20˚C




3 25˚C




Table 2 : Results for Experiment 2
Table of the different temperatures used against the rate of electrolysis



No comments:

Post a Comment