I want to find out the affect current has on copper sulphate solutions as I increase the voltage.

Apparatus:

The equipment I will need is as follows:

• Small beaker - to hold copper sulphate solution in.

• Copper sulphate solution - to be put in the beaker.

• Carbon electrodes -

• Power pak – where the current will be coming from.

• Ammeter – to read the amount of voltage each time.

• Wires – to transmit current through.

• Weighing machine – to weigh the carbon electrodes for results in grams.

• Watch – to check that it is always 5 minutes as each time the volts are increased.

Here is a simple diagram of my experiment on electrolysis:

Fair test:

To make this a fair experiment, I will check every time that I increase the volts only every 5 minutes, no more or less, to do this precisely I will use a watch to time myself. Each time I will do the same test with the same amount of volts to see if my outcomes are familiar, this will then ensure me that I am doing it correctly and according to plan. I will use the equipment with care, safety and also obey all school science lab rules.

Method:

Below I will write down the step-by-step procedure in which to follow to do this experiment.

1. Collect all equipment needed and set up according to the demonstration.

2. Collect 50ml copper sulphate solution and pour into small beaker. (Making sure that the solution is reasonably touching the electrode).

3. Weigh both the anode (+) and the cathode (-) at the beginning of the investigation.

4. Make sure all wires are working appropriately and all the other equipment, and then begin the experiment.

5. Start off with 2 volts and for each bear in mind to only leave it to a standard 5 minutes. After the 5 minutes weigh both electrodes separately and record the results into a table.

6. Repeat steps 5 again, only this time increase the current to 4 volts then 6 up until 12. Remember to record the outcomes into a table each time.

Results:

Here is what I am going to use to record my results in:

Here are the actual results, which I obtained from the experiment:

Graph:

From my results I drew up a line graph stating my results, here it is:

 

Conclusion:

After carrying out this investigation, I have noticed that I have learnt many new things about electrolysis than I knew before. I have learnt about the two main parts of the experiment, off course, I am talking about the pieces of carbon graphite, the cathode (-) and the anode (+). I have learnt that the cathode, which is the negative terminal, attracts the copper ions, which are positively charged. However, the other piece, the anode is also extremely important as it usually attracts the non-metal in turn separating the solution copper sulphate (CUS04) into the elements copper and sulphur.

I have noticed that my prediction was correct; this was because what I predicted funnily enough occurred. This was of course that as the current was increased the rate of electrolysis would speed up, which it did. However, as for the anode (+) the results were interesting due to its one-way result. The anode weighed 1.5 grams all the way through. The anode did not attract any element, therefore, it didn’t get heavier like the cathode, and instead oxygen gas was given off at the anode.

In general, the line graph shows the results, it has a peculiar cathode line, which seems reasonable. The graph shows that the cathode is increasing in mass during electrolysis and this clearly indicates, as the current is increased the cathode gets heavier and heavier by getting coated with copper. The line indicating the anode shows that no changes in the mass of the anode have taken place as predicted.

Bearing in mind, electrolysis can be used to extract many other metals besides from copper, aluminium being one example. Electrolysis in the existing world, is one of the common uses of metal extraction, it is widely used.

Evaluation:

All in all, I have enjoyed this investigation and I believe that my results were fairly accurate and reasonable. I can say that my method was an easy and firm procedure in which to follow, I had no difficulties with it. However, to ensure that my experiment was a fair test I kept the time (5 minutes) same throughout the investigation when I changed the current each time. I also made sure I had followed all rules and my method in order to obtain firm results. But I later realised that I could have dried the electrodes (anode and cathode) before weighing them, this is because water probably made the electrodes slightly heavier than it should have been. I did not have enough time to do this that is why it was left out.

Finally, if I had the chance to improve my results I would have changed a few things so that my outcomes would have been extremely reliable. For example I could have got even more reliable weighing machines because the ones we used were not exact. I also could have compared 2 or 3 results and worked out the average for it, although I didn’t have enough time in order to do this. Subsequently, as I have mentioned before each time I changed the current I could have changes the electrodes so that water didn’t affect it as much. In general, these are the aspects of the investigation I could have improved if I did it again. I could have researched in more depth for a better conclusion and a firm investigation.