Crystallisation of Copper Sulphate Dcp

Mass of crucible Mass with cuSO4 Mass after heating Difference in mass 29.50 34.50 32.66 1.84 30.40 35.40 33.56 1.84 26.37 31.37 29.54 1.83 29.50 34.50 32.66 1.84

Moles of water = mass/mr
= 1.84/18
=0.102
CuSo4 moles = mass/mr
= (5 - 1.84) / 160
= 3.16 / 160
= 0.01975
0.102/0.01975
= 5.16 moles

Conclusion: The results show that the difference in mass between the experiments differed by .001. This means each repeat was done in a very similar manner how ever there was a 0.97% error as the true value should have been 5 this could have been caused by a miss read of the scale or some other anomaly.

Evaluation: This experiment went well there was not manny problems that could cause a major change in the results, however I noticed that some of the crystals stuck to the stirring rod this could decrease the ending mass too much. Additionally there was a soot buildup on the bottom of the crucible however these are minor and wouldn't make much of a difference. To be precise I used a top hand balance that measures to two decimal places.

Improvements: In order to solve the issue of the crystals sticking to the stirring rod could be solved by adding the rod to the scale and measure it with the crucible both before and after then deducting it. Additionally it could be solved by being extra cautious and making sure you remove the crystals from the rod on the side of the crucible.