Purpose: The purpose of this lab is to find out how Copper sulfate interacts with water when exposed to heat and dehydrated, when rehydrated, and what the physical properties of it are in these states. I presume that once the water is removed, the copper sulfate will weigh much less, because of the loss of matter to evaporation.
Data and Calculations:
Copper sulfate: CuSO4•xH2O
Original copper sulfate: blue crystals, look a bit like tiny rice, lodge themselves together well – resist rolling around when container is tilted.
When exposed to heat, immediately begin to turn white on the bottom of the dish. After continuous stirring, the entire mixture became blueish white. The crystals disappeared, and only clumped powder remained. After continued heating, powder clumps separated, and the matter became completely gray-white.
| Subject | Weight |
| Dry, empty dish | 21.59g. |
| Dish with blue crystals | 25.90 |
| Semi-dehydrated crystals | 24.54 |
| Dehydrated crystals | 24.42 <= Palindrome |
After a bit of water is sprinkled onto the powder, it becomes blue immediately, while hissing and launching some debris more than a half of a foot into the air. The matter in the dish turns into a solid circular block of crystalline material which I proceeded to crack with the metal rod.
Net weight of the chemicals:
| Subject | Mass |
| CuSO4•xH2O | 4.01 |
| CuSO4 | 2.53 |
| H2O | 1.48 |
Results/Discussion: It is clear from this lab that these blue crystals of Copper sulfate definitely contain water, which takes up almost half of the mass. By heating 4 grams of the crystals, I was able to remove 1.5 grams of water! The answers seem right, because the objective of the lab was the interaction of Copper sulfate and water, and there was definite interaction visible in the experiments. Not only did the mass of the substance change after it was heated, but it also had a dramatic change in color – blue to grayish-white. Some possible errors that may have been made include carelessness which could result in the oxidation of the Copper sulfate (burning), loss of the substance via dropping the dish, and not waiting for the dish to cool before weighing, which may result in a different mass than the true mass. My hypothesis was correct, because the copper sulfate lost a large amount of mass when it was heated, which was because the water evaporated from the crystals. I am actually not sure how this relates to what we are currently learning in class.
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