Investigating The Electrolysis of Copper

Investigating The Electrolysis of Copper

Two copper electrodes are cleaned, dried, weighed and attcahed to a

power pack. One is attatched to the anode and the other is connected

to the cathode. Then both the copper electrodes are placed in a beaker

of copper sulphate solution (which is acting as the electrolyte) and

the power pack is turned on. After a certain amount of time the copper

electrodes are detached and the cathode washed in distilled water,

then acetone and weighed when dry. There are many variables I could

change that would affect the the results of this experiment, these

include:

· The amount of solution

· The current

· The amount of time the power pack is left on

I have chosen to change the current flowing through and keep

everything else the same. I will use 50ml of copper sulphate solution

and the electrolysis will take place for 10 minutes(or 600secs).

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Prediction:

For the first test I will use 1.15A. I will repeat the experiment

using the same amount of current and then raise it by 1A. Because the

change is so gradual I should get a good idea of what happens, but the

change isn't so small that there isn't a good range of results.

I think that the copper on the anode will dissolve sending cations

into the electrolyte. These cations are attracted to the negative

charge of the cathode and so get attached to the negatively charged

copper electrode. This means that the weight of the anode should

decrease after electrolysis and the weight of the cathode should

increase.

The formulas for the reactions taking place at the anode and the

cathode are as follows,

Anode Cathode

[IMAGE][IMAGE]Cu(s) Cu ² (aq) +2e־ Cu ² (aq) +2e־ Cu(s)

Also I have worked out roughly the amount of copper that should be

deposited when there is a current of 1.15A and the time of

electrolysis is 10 minutes.

Time of electrolysis = 10min = 600 sec