The Electrolysis Of Copper Sulphate Solution Using

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The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes Essay, Research Paper Planning I did some preliminary work to see which current values, and for how long to time. The results of this are in the tables below: Electrode-1AMass before (g)Mass after (g)Mass change (g) Anode1.381.30-0.08 Cathode1.351.65+0.30This was done for 10 minutes. The mass lost at the anode should equal the mass gained at the cathode, which this doesn’t, it has a percentage inaccuracy of 0.22¸ .30×100= 73% which is very inaccurate, This may be due to the current being too high, so the copper does not all transfer properly, but lies on the bottom of the beaker, therefore a lower current must be used, as in the table below: Electrode-0.1AMass before (g)Mass after (g)Mass change (g)

Anode1.421.35-0.07 Cathode1.161.21+0.05This was also one for ten minutes, and shows much more accurate results, as the percentage inaccuracy is only 0.02¸ 0.07×100=29%, which is still inaccurate, but is a lot better . This could be due to the current value being to low, so I will take a range of 5 results from 0.1Amp to 1Amp at 0.2Amp intervals. Each electrolysis will last 10 minutes, and each will be repeated twice so that a more accurate average can be taken. Variables *Temperature of the electrolyte *The concentration of the electrolyte *The separation of he electrodes *The size of the electrodes *Current Only the mass or size of the electrodes, and the current are being investigated, therefore in order for this to be a fair test, the other factors must be kept constant. The

temperature was monitored during the preliminary results, and the higher the current the higher the temperature change, which in the 1A reading was 5° C, therefore to keep it as constant as possible the current will be as low as possible, and monitored, so that it does not change during the experiment There will be a thermometer in the electrolyte so that the temperature can be monitored. The same CuS04 will be used throughout so the concentration is the same, and the same spacing between electrodes will be used. The size of the electrodes should be the same, but they will be reused, so the size will change from experiment to experiment. Method *scrub copper electrodes with wire wool *rinse in distilled water *dry with propanone *weigh and record anode and cathode *put into

circuit ate set current value, with crocodile clips, making sure the clips are not touching the copper sulphate. *time for ten minutes *remove and dry, weigh and record result The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes Method and Obtaining Evidence Diagram Obtaining evidence Current (amps)Anode before (g)Anode after (g)Mass loss (g)Cathode before (g)Cathode after (g)Mass gain (g) 0.21.391.36-0.031.331.380.05 0.21.351.31-0.041.371.400.03 0.2 average1.371.34-0.041.351.390.04 0.401.291.20-0.091.401.480.08 0.401.201.18-0.021.471.570.10 0.40 average1.251.19-0.062.871.350.09 0.601.010.91-0.100.981.110.13 0.600.980.89-0.090.921.060.14 0.60 average1.000.90-0.100.951.090.14 0.800.910.75- 0.800.720.57- 0.80

average0.820.66- 1.000.700.54- 1.000.680.55- 1.00 average0.690.55- The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes Analysis There are two straight lines of best fit through the origin , the red one is the mass gained at the cathode, and the pencil one is the mass lost at the anode. The lines are nearly as they should be, which is equal, as the mass lost at the anode should equal the mass gained at the cathode. This is because as explained in the planning, the reaction occurring at the anode,: Cu(s) (r) Cu2 +(aq)+2e- (oxidation) during the electrolysis of a copper salt is the reverse of the cathode reaction: Cu2 +(aq) + 2e- (r) Cu(s) (reduction) So for every two electrons passing through the