Question

Experiment 3: Determination of Percent Water in a Hydrate Data Sheet Run #1 Run #2 _37.032 g Mass of crucible and cover 38.067 g Mass of crucible, cover and hydrate Mass of hydrate taken for 2-1- analysis 38.Ona _37.713 g Mass of crucible, cover and residue (after heating) _8 - Mass of H20 lost 6. _(FW=18.015 g/mol) mol Moles of H20 lost 13 3521 % % Percent of H20 lost .8 Mass of residue (anhydrous salt) mol Moles of anhydrous salt (ZnSO4). 161.443 g/mol Molecular weight of anhydrous salt (obtained from your instructor) Number of moles of water per mole of unknown hydrate (round off to whole number)

Answer 1

3. 1.035 gm

5. 0.354 gm

6. n= w/gmm = 0.354/18.015 = 0.0196 mol

7. (100*0.354/1.035) = 34.20%

8. 1.035-0.354 = 0.681 gm

9. 0.681/161.443 = 0.0042 mol