Lab 4C: Formula of a hydrate

Objectives:
1.to determine the percentage of water in an unknown hydrate
2. to determine the moles of water present in each mole of this unknown hydrate, when given the molar mass of the anhydrous salt
3. to write the empirical formula of the hydrate.
Table1
Mass of empty crucible: 10.14g
Mass of crucible lid and hydrate: 11.20g
Mass of hydrate: 1.06g
Mass of crucible, lid and an hydrous salt(1st): 10.83g
Mass of crucible, lid and an hydrous salt(2nd): 10.81g
Mass of anhydrous salt: 0.67g
Mass of water given off: 0.39g
Mass of one mole of anhydrous salt from instructor: 159.6g/mol

1. 0.39g/1.06*100%= 36.8
2. 0.67g/159.6g/mol= 0.0042mol
3.0.39g/18g/mol=0.022mol
4. moles of water/ moles of CuSO4= 0.022mol/0.0042mol= 5
5.CuSO4 5H2O