CuSO4

Please see the attached file.

1. CuSO4.5H2O was heated such that the waters of hydration were driven off leaving the anhydrous salt. Calculate the percent change in mass as a result of dehydration.
Atomic weight of Cu = 63.55 grams/mol
Atomic weight of S = 32 grams/mol
Atomic weight of O = 16 grams/mol
Atomic weight of H = 1 grams/mol
Molecular weight of CuSO4 = 63.55+32+4*16 = 159.55 grams/mol
Molecular weight of H2O = 18 grams/mol
Percentage change in mass =

2. When conducting the experiment to drive of the waters of hydration in alum to yield a less hydrous salt, would it be more difficult to do on a very hot and humid day in August? Why or why not?
Alum is highly hygroscopic and it would readily reabsorb water of hydration from ambience on a hot and humid day. That is why it will be more difficult to do it in a hot and humid day.