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Chemistry 103/113 Laboratory |
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This Week |
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Expt 6: Photochemical Blues (week 1) o
Purpose/Procedure/Week
1 Data · Week 1 report due tomorrow |
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Next Time |
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Expt
6: Photochemical Blues (week 2) |
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Notes for Today |
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Photochemical Blues (Week 1) ·
Overview: o
Synthesize/purify K3Fe(C2O4)3.3H2O (Week 1) o
Qualitative tests
for K+, Fe3+,
C2O42- (Week
2) o
%Fe photoreduction
assay (Weeks 2,3) o
Make blueprints (Week
3)
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Synthesis: FeCl3(aq) + 3K2C2O4(aq) + 3H2O(l)
-> K3Fe(C2O4)3.3H2O(aq) +
3KCl(aq) o
Precipitate
the salt on ice §
Why use ice? §
K3Fe(C2O4)3.3H2O(s) forms §
FeCl3, K2C2O4, and KCl are very soluble and stay in supernatant §
Decant and measure supernatant volume o
Recrystallize the salt o
Vacuum
filter the salt
o
Rinse with drying solvent §
How can rinsing with
a liquid dry the salt? §
Methanol and water
are miscible in all proportions §
Methanol is more volatile than water (evaporates more
quickly) §
Why is the salt
insoluble in methanol? o
Test the salt
for chloride contamination o
Store the salt
in a capped sample vial in your drawer. §
Why store in the
dark? ·
Safety
Issues o
Splash hazard. Goggles required. o
Vacuum filtration
hazards o
Methanol is
flammable
o
Wash hands
frequently |
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