Finding the Change in the Mass of the Electrodes During Electrolysis

Finding the Change in the Mass of the Electrodes During Electrolysis

Safety:

Before carrying out he investigation we had to take safety into

consideration so we wore goggles to protect our eyes from any harmful

chemical and aprons to protect our clothes from anything that may get

spilt.

Equipment:

1x 250 ml glass beaker

1x power pack

1x ammeter

4x wires

Copper Sulphate solution

2x Copper electrons

1x Variable resistor

Weighing scales

1x stop clock

Propane

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Method:

Set up the apparatus as shown above in the diagram. In order to

collect evidence that was valid we made sure the copper electrodes

were thoroughly clean by removing any old copper with wire wool to

ensure a fair test. We put both pieces of copper in a 250 ml glass

beaker that was filled with CuSo4 (electrolyte) solution. We then used

the power pack and the variable resistor to set the current at (a

pre-decided) 1Amp.

Firstly we weighed and recorded the mass of the positive and negative

electrode (Anode and Cathode). Using the stop clock for accurate and

fair timing, we recoded the mass of the electrodes at 5, 7,9,11 and 13

minuets. We then repeated this procedure twice more to obtain a good

set of results.

(In the second and third experiment we decided not to record the

change in mass of the negative electrode because we felt there were

too many things that could alter the accuracy of the result, such as

water washing of newly formed copper or even newly formed copper being

lost in the solution or being brushed of onto aprons accidentally,

resulting in an unfair test).

The results are shown in the table below.

Prediction:

I think that more copper should be deposited on the cathode (negative

electrode -ve) so it's mass should increase. This is this is because

the positive copper ions (Cu2+) are attracted to the cathode from the