Lab 9: Composition of a Copper Sulfate Hydrate Lab

Before heating the hydrate

After heating the hydrate

Data

Mass of Evaporating Dish - 25.40 grams

Mass of Evaporating Dish + Hydrate - 26.88 grams

Mass of Evaporating Dish + Anhydrous Salt - 44.1 grams (1st heating) 

Mass of Evaporating Dish + Anhydrous Salt - 43.7 grams (2nd heating)

Mass of Evaporating Dish + Anhydrous Salt - 43.74 grams (3rd heating)

          Since our percent error was so high, it is likely that our actual empirical formula would be different. I predict that there would actually be more copper sulfate molecules per water molecule in the empirical formula. I believe that our results had such a high percent error because we incorrectly massed the evaporating dish at the beginning of the experiment, leading to incorrect results the rest of the way through the experiment. This may have been because the scale was tared and we did not realize it or for another reason, but looking at the data, the evaporating dish should have logically massed almost twice as much as we had previously found.