| Pre-lab Discussion: This experiment is
intended to introduce students to hydrated compounds.
These compounds have water molecules coordinated in
their chemical structures. Examples CuSO4●5H2O,
BaCl2●2H2O,
and NaC2H3O2●3H2O.
Notice each formula has a "●"
between the compound's formula and the number of water
molecules that are coordinated in the structure. the
"●"
represents a weak chemical bond known as a hydration
bond. This bond is usually easily broken by heating the
compound.
I. Objective: To experimentally determine the percent
composition of water in CuSO4●5H2O
II. Materials & Equipment:
Crucible
crucible
tongs
scoopula
balance
CuSO4●5H2O
burner
ring stand
iron ring c lay triangle
flint sparker
III. Procedure:
1. Mass a clean dry crucible.
2. Fill the crucible about 3/4 full of hydrated copper
(II) sulfate, CuSO4●5H2O.
3. Mass the crucible and hydrated copper (II) sulfate.
4. Heat the hydrated copper (II) sulfate for 10
minutes.
5. Mass the crucible and cover with the anhydrous copper
(II) sulfate( CuSO4).
IV. Data:
_____________ g Mass of Crucible and CuSO4●5H2O
_____________ g Mass of Crucible
_____________ g Mass of CuSO4●5H2O
(hydrated copper (II) sulfate)
_____________ g Mass of Crucible and CuSO4
(After Heating)
_____________ g Mass of Crucible
_____________ g Mass of CuSO4(anhydrous
copper (II) sulfate)
_____________ g Mass of CuSO4●5H2O
(hydrated copper (II) sulfate)
_____________ g Mass of CuSO4(anhydrous
copper (II) sulfate)
_____________ g Mass of Water (Driven off during
heating)
V. Questions and Calculations:
1. From the video calculate the experimental percent
composition of water in hydrated copper (II) sulfate
(CuSO4 ●
5H2O).
2. Calculate the theoretical percent composition of
water in hydrated copper (II) sulfate (CuSO4 ●
5H2O).
3. Calculate the percent error.
VI. Conclusion:
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