Electrolysis Investigation

GCSE: Chemistry

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The results seem reasonable. As the current flows for a longer period of time, more copper is lost from the anode and deposited at the cathode. This is as, current flowing for longer will mean more electrons will be available that will be able to react with the copper easier and quicker. The results for mass lost are very similar to the results for mass gained at the other electrode; these would, theoretically, be exactly the same values if there were no errors.
The graphs have very strong positive correlation and not many points are far from the lines of best fit. This shows that not many errors occurred and the conclusions I make can be deemed accurate.
The lines of best fit are almost parallel, which shows definite accuracy as they should have the same (as they would have had the same values) in theory. I also noticed that the graphs’ errors did not match. I believed, at first, that the distance that one point is above the line (for the anode), would be the same as the distance that the corresponding point is below the line (for the cathode). This was not correct, however, as there is only one error on the anode graph, but there are two errors for the cathode graph. This shows that the errors were not linked and may have been more affected by the flaws in carrying out the experiment than the possible flaws in the copper (e.g. rust) or the solution (concentration etc).
Finding the equations of the lines of best fit allows us to predict how much copper would be deposited in any set length of time.
I will now work out these equations using:

y = mx + c (m = the gradient; c = the intercept of the y-axis)
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