Method:
1. The apparatus was set up as shown in the diagram below.
2. 2-3 spatulas of blue copper (II) sulphate were placed in the crucible.
3. The powder was heated until it had gone completely white, but was not heated so strongly that it starts to blacken.
4. The powder was allowed to cool and then reweighed.
5. All the results and observations were recorded carefully.
6. The experiment was then repeated.
Results:
This is the raw data collected:
The data was then processed to see how much water had evaporated:
The data from Trial 1 was then used to calculate the empirical formula
Then the same process is carried out for Trial 2:
Conclusion:
From the results obtained, it seems like the empirical formula of the compound is CuSO4 . 5H2O or CuSO4 . 7H2O . However, the theoretical result we should have obtained is CuSO4 . 5H2O . Hence, there have been some large errors in the second trial. The results wasn’t taken as an average of the two results obtained, as the second results was erroneous due to mistakes made during the experiment.
Evaluation:
Evidently, the first experiment was quite accurate, as the theoretically expected results were achieved. However, the second experiment was grossly inconsistent, which indicates that there have been some random errors. The second set of results is faultier, but this is because some of the Copper Sulphate fell out of the crucible while measuring its mass.
