Data:
Table 3: Determine the Percent Water in a Sample
| Parameter | Trial 1 |
| Mass of crucible, lid and hydrated salt (g) | 37.6102 g |
| Mass of crucible, lid and anhydrous salt (g) | 36.9600 g |
| Mass of crucible and lid (g) | 35.8490 g |
| Mass of hydrated salt (g) | 1.761 g |
| Mass of anhydrous salt (g) | 1.111 g |
| Mass of water lost (g) | 0.65 g |
| Percent of water in the hydrated salt | 37% |
| Number of moles of anhydrous salt (mol) | 0.006960 mol |
| Number of moles of water lost (mol) | 0.036 mol |
| Ratio between salt and water | 1:5 |
| Formula of hydrated salt | CuSO4 * 5H2O |
Calculations:
1. Moles of anhydrous salt
2. Moles of water lost
3. Ratio between salt and water
Ratio of salt to water 1:5
1 mol of CuSo4 : 5 mol H2O.
Percent of water lost
Percent error
Analysis and Conclusion:
The purpose of this lab was to find the percentage of water in a hydrate. To accomplish this the sample was heated to dehydrate it. Then that mass was subtracted from the original mass to determine the amount of water. Then the percentage was found to help determine the empirical formula. The empirical formula of hydrated CuSO4 is CuSO4 * 5H2O. The results obtained from the experiment was 1 mol of CuSo4 : 5.2 mol H2O. When it is rounded to the nearest whole atom it becomes 1 mol of CuSo4 : 5 mol H2O. which is the accepted value. The percent of water lost in the hydrate was 37%. Because the right ratio of anhydrous salt to water was found in the experiment, the amount of water lost is around the right number. The data supports the hypothesis that a ratio of 1 mol of CuSo4 : 5 mol H2O would be found. Some sources of error in the experiment could be from not heating the sample fully to remove all of the water content from it since more moles of water were obtained than the actual accepted value. If the experiment were to be performed again, the sample should be heated for a longer time to remove more of the water to receive more accurate results. Another way to improve this experiment would be to do more trials of it. Because there was not enough time, it could not be done for this experiment.