Electrodes are plates of a conducting material by which current enters and leaves the ionic compound called the electrolyte. The negative electrode is called the cathode by which it collects the copper mass, the positive electrode is called the anode by which it gives out mass of copper.
4)Variables and Controls:
I have a varies topics which I could choose a variable from, these are;
- Time taken
- Current
- The size of electrons
To make this controlled investigation I must keep the factors constant and only have one factor that could be changed which is CURRENT. This means that I must change only CURRENT and not any other variable to keep the others constant.
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The independent variable: (things that you change)
The things that I will be changing in this investigation into the factors affecting Electrolysis, is the current this helps me to see hoe this has an effect on the investigation.
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The dependent variable: (things I measure)
The things that I’ll be measuring in this investigation on electrolysis is the time of how long the experiment will go on for. Also I will be weighing the cathode to see the change in mass.
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The fixed variable: (the things that you keep the same)
The things that I have chosen to keep the same in each individual experiment to keep the test varied is to keep the time for ten minutes each. The use of the same cathode and anode.
5)Apparatus I will need:
- Ammeter
- Stopwatch
- Auto Rip
- Power supply
- Beaker
- Copper sulphate solution
- copper electrodes
6)Diagram
7)Safety Procedures:
safety is an important aspect in every experiment seems to very harmless. This is why I’ll be taking this into consideration. I will be using electricity to flow to flow through the circuit, which could power shock someone if hands are watery. I should also make sure that copper sulphate solution doesn’t enter our bodies in any way.
8)Results Table:
A table to show the amount of copper deposited in the cathode.
9)Graph:
a graph to show the change in mass (g) in the cathode.
10)Method:
This investigation was carried out by pouring copper sulphate solution into the beaker. The cathode electrode was thoroughly cleaned using sand paper, to clean any of the layers from pervious experiments. The cathode was then weighed , the mass was recorded in a table and placed in the beaker containing copper sulphate solution. The electrodes were connected to the ammeter, auto rip and power supply . a steady time was taken of ten minutes on the stopwatch and the experiment contained different amps
( 0.2, 0.4, 0.6, 0.8 in amps) by moving the power supply changed the moving the variable resistor I changed the power of the current in amps. The power was turned off and both the Electrodes were taken out of the copper sulphate solution. The cathode was washed by dipping into propane and placed in an electric heater once cleaned the cathode was carefully weighed.
11) Conclusion:
The evidence from this investigation supports the prediction I made: -
“ In this investigation I will predict that if a bigger amount of current is used the amount of copper deposited will increase.”
I believe that I have collected enough data to support my prediction. I think this investigation was successful.
The results were fine and by looking at the weights measured before and after the experiment you can clearly see the change mass. I believe by looking at my results that the cathode was scrapped off properly.
The graph and the results show that the higher the amount of current the more the mass is gained on the cathode.
There doesn’t seem to be any results, which undermine my predictions and I didn’t find any odd results, which means I didn’t have to repeat
the results more than twice. Having the results, which backs up my prediction, proves that this investigation was fully accomplished, and was achieved. This investigation helped me to find out the aspect of the current in electrolysis.
12) Evaluation
I believe that gained accurate and sufficient enough results, shown on my graph and tables that concludes the investigation, and prove my prediction. My final results were very reliable, due to the variables I took made this a fair test.
Looking at the overall experiment I have thought of a number of improvements to give more accurate results Firstly the cathode had
already been used in other experiments. Then the copper sulphate was not measured of how much should be used, the distance of the two electrodes were not measured.
To make this experiment better, I believe that I could have done one more test so it would become more accurate to get the average results better.
Although this was a successful experiment, there were some factors of the experiment, which could have been improved to make it even more successful. One of these factors could have been the electrodes, which, even after a good clean were still quite dirty and obviously still had irremovable substances from previous experiments still attached to them. If this experiment were to be repeated for a second time, in need of greater accuracy, it would be imperative to have a new pair of electrodes, which have never been used before.
Another factor which may have affected the overall outcome of the investigation, may have been the fact that the practical work of the investigation was carried over from lesson to lesson, meaning that variables such as the concentration or the amount of the Copper Sulphate solution could have changed between lessons. To overcome this problem, a stock solution of Copper Sulphate should have been made so as the concentration remained the same at all times. The same electrodes and equipment should have been used throughout. Also,
when weighing, the same electrical balance should have been used, as there may have been slight differences between the two balances. I found this investigation very interesting and I am looking forward to investigating more of the variables in this experiment, which may or may not affect the mass of copper deposited onto the cathode, such as changing the Current or Temperature variable.
