Electrolysis in that the metal deposited from electrolysis plated out on the surface of another metal.
Electrolysis is the break down of a substance by electricity. Electrolysis only occurs in when an ionic substance is molten or is in solution, a substance that can be electrolysed is called an electrolyte.
Risk Assessment
I will wear safety goggles and plastic gloves because sulphuric acid is corrosive, would damage my skin and my eyes. I will add the acid slowly to the malachite so that no acid spits out. If any acid spills I will wash it with lots of water.
Apparatus
Beaker
Balance
Spatula
Carbon Rod
Measuring cylinder
Ammeter
2 crocodile clips
sulphuric acid
Wires
Power supply
Method
I will weigh 2g of malachite into a beaker. Then I will measure 50 of sulphuric acid and add it slowly to the malachite. I will weigh the carbon electrodes. These will be placed in the solution of copper sulphate in the beaker and connected to an electrical circuit in the experiment, which was connected to the power supply. I will set the power supply to 2 volts and pass the current through the solution for 20 min. Then I will turn of the power and remove the carbon electrodes and weigh them. I will calculate the amount of copper that has been formed on the electrode. I will do this experiment for 3 times, when I get the results from the experiment then I will record it in table. I will calculate the yield of the malachite for each result. To calculate the yield I will use this formula:
%Yield = Carbon after-Carbon before
Malachite
CuCo3+H2So4 CuSo4+H2o+Co2
Results
Results
A
The for finding out the yield is:
%Yield = carbon after- carbon before
Malachite
The percentage yield for the first one is: 0.25g * 100% = 12.5%
2g
The percentage yield for the second is: 0.43 * 100% = 21.5% 2g
The percentage yield for the third is: 0.26 * 100% = 13%
2g
Analysing the results
Each time when done the experiment I got different amount of yield on the carbon rods. I think I might have not measured the rods properly or malachite. It might be because of the current was more then required or the when I was taking out the rods out of the solution the copper might have been fallen of it. In all the experiments the carbon rods weigh more after then before. It means that the experiment were correct. The amount of copper I had one the second one is much greater then the others it might be because I left the rods in the solution too long. My results suggest that if the copper I got on the rod is greater then the percentage yield will be greater as well. The rods weigh less when there is no copper on it but weigh more when it has copper on it.
Evaluation
The aim of the experiment was produce pure metal in the laboratory. My results show that my experiment was correct but not accurate. There are many reasons why the experiment was not 100% accurate. One of the reasons of not getting the accurate results is that I might have measured the rods and the malachite incorrectly. I might have had the wrong voltage through the solution. The copper on the cathode might have been dropped when I was trying to measure the amount of copper on the rods.
The results were not accurate because the colour of the solution didn’t change from blue, which means that not all the copper went to the cathode.