Apparatus.
- Goggles.
- Electrolysis Cell.
- 6-Volt Power Pack.
- Distilled Water.
- Sodium Chloride.
- Measuring Cylinder.
- Ammeter.
Diagram.
Power Pack.
Ammeter
Anode Cathode.
Beaker
Sodium Chloride
Solution
Fair Test.
To keep this experiment fair then I will only change one of the variables. The variable that will change is the concentration of the Sodium Chloride Solution.
Method.
- Collect all the equipment listed above.
- Choose the concentration that you will be using for the first experiment.
- Collect some distilled water and make sure that it is pure water and doesn’t contain any impurities.
- Collect the power pack and set up the dials so it will omit 6 volts.
- Pour the sodium chloride solution into the electrolysis cell. The cell will hold approximately 20ml.
- Turn the power pack and then electricity will flow through the solution.
- You will be able so see a reaction taking place at the anode and cathode. The gas given off should be hydrogen.
- Repeat another 2 times so you have a set of 3 results and will be able to find an average. You could do this by just turning off the power pack and then turning it back on again.
- Now once you have done this experiment and recorded the results. Now you will change the concentration of the sodium chloride solution by adding more or less distilled water to it.
- NOTE You will need about 6 sets of different concentration results.
Safety.
- Wear goggles at all times.
- Do not inhale the chlorine.
- Do not turn the voltage up to over 6 volts.
- Do not alter the power pack with wet hands.
Results.
Analysis.
From this experiment we can see that the results which we found supported our original prediction. We predicted that as we increased or decreased the concentration of the Sodium Chloride, the current would increase too. We can see from the graph that the line of best fit is angled at a diagonal upwards. This is because the current is increasing and so as we increased the concentration then the current would increase too. At the negative electrode (cathode) the sodium ions were attracted to it and at the positive electrode (anode) the chloride ions were attracted to it. I also found out that the higher the concentration of the solution meant that there would be more ions and had a higher current flowing through the electrolyte.
When observing this experiment, I saw that there were bubbles of chlorine gas coming off of the anode, I knew that it was chlorine gas because I could smell it. This also proves that my prediction was correct.
Evaluation.
The results that I got from this investigation were quite reliable, but they would have been more reliable if I had done each part of the experiment more than three times each. This would have given me a wider range of results The more times you do the experiment, the more accurate the results. Therefore you would get a better average. In my results I did find an anomalous result, so this shows that the experiment went wrong somewhere and so the results are not perfect.
I could have improved the experiment by using a larger quantity of the solution.
I think the evidence was reliable enough to confirm a conclusion, because chlorine was found coming off of the anode, which means that electrolysis is a good method of separating a solution of Sodium Chloride and water.
I think that to improve my experiment I would take more time to carry out the experiment and I would also use a more accurate measuring cylinder to collect more accurate results. I think that I carried out my experiment very well and I am confident that I used every safety procedure that I stated in my ‘Safety’ section of my plan.
How to extend my experiment.
- I could have used a wider range of Sodium Chloride.
- Use a bigger electrolysis cell so I can use a larger amount of solution.
- Use a larger current.
- Use different variables.