Experiment 5 write-up guidelines
approximate point breakdown by section and brief section descriptions
prelab 10 pts
should include balanced reaction(s), cmpd physical constants,
theoretical yield(s), potential hazards, and procedure outline
should also contain observations and data recording during lab
mechanisms of reaction(s) 5 pts
results of experiment 30 pts
turn in product with complete labeling (4) - label should include
student name, date, sample name or structure, weight, mp range
report weight (and % yield) of crude and recrystallized product (8)
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product purity (12) - determined by appearance, mp range, and TLC of
purified product
TLC plates (6) - turn in 3 TLC plates run in different solvents;
plates should be labeled and baseline, solvent front, and spot
positions should be marked in pencil.
NMR spectra presentation /
interpretation 15 pts
presentation of H-NMR spectra of starting materials (student
makes assignment) and representative product benzhydrol sample from
student's section
a summary (text form) of each H-NMR spectra (as would be reported
in the experimental section of a publication)
assignment of all protons in the molecules to their signals in the
spectra
comments about any "extra" signals observed in the spectra and their
possible origin
TLC results 10 pts
report of Rf values and identification of components in crude and
purified product (based on standard sample and/or best guess)
discussion 5 pts
a breif discussion of how the experiment went, any interesting or
notable observations, any particular difficulties encountered, and
any special procedures or purification techniques used. compare crude
and purified product appearance, mp's and TLC results. disucss which
TLC conditions gave the best separation.
conclusion / learning experience 7 pts
in summation, what was accomplished in the experiment and what
was learned by the student. make conclusion about final purity of
product and the effectiveness of the recrystallization, based on mp
and TLC results.
questions 8 pts
experiment 13.1 - questions 1, 3
technique 10 - questions 1, 3
technique grade 10 pts
evaluation by TA and instructor of student's lab technique, use
of proper set-ups, cleanliness, attention to safey, general
attentiveness to details of lab procedures and rules