Chemistry 201 Laboratory
Fall, 2003
Instructors:
Thomas S. Straub, Holroyd 302, Phone: 215-951-1263, email: straub@lasalle.edu
William A. Price, Holroyd 307, Phone: 215-951-1261, email: price@lasalle.edu
Required Materials:
(1) Laboratory Text: Modern Projects in Organic Chemistry, J. R. Mohrig,
C. N. Hammond, P.F. Schatz and T. C. Morrill, W. H. Freeman, 2003.
(2) Approved safety goggles with side protection. Prescription or reading glasses
alone are not suitable substitutes. Safety goggles are normally designed to
fit over such glasses. Also, because of the hazard associated with vapor irritation,
the use of contact lenses in the lab is discouraged. Approved goggles can be
purchased at the chemistry department stockroom.
(3) A laboratory apron will be required at all times in the lab. Black rubberized
aprons can be purchased at the chemistry department stockroom.
(4) Rubber gloves that are rated solvent resistant.
(5) A bound laboratory notebook with numbered pages will be required. This can
also be purchased at the stockroom.
(6) A pocket calculator with basic functions is recommended.
(7) A breakage card is required and should be brought to each laboratory meeting.
This should be purchased at the stockroom before the first meeting.
Laboratory Objectives:
The primary objective of the laboratory program for the Chemistry 201-202 sequence
is to exemplify, through experimentation, the basic principles of Organic Chemistry.
In actuality, the Chemistry 201 lab will emphasize traditional laboratory techniques
suitable for a first course in Organic Chemistry. These techniques will include
recrystallization, extraction, reflux, distillation and the determination of
melting and boiling points. Each of the above may be done as a discrete operation,
or in combination with other techniques. These basic techniques will form the
foundation for performing later experiments primarily involving synthesis and
structural analysis of organic compounds. In addition, instrumental techniques
including Gas Chromatography (GC), Infrared Spectroscopy (IR) and Nuclear Magnetic
Resonance Spectroscopy (NMR) will be introduced in the 201 course and expanded
to include additional experiments in Chemistry 202. Since a major objective
of the Organic Chemistry laboratory is to learn a large number of totally new
laboratory techniques, you will be carefully observed on the safe and proper
methods for implementing these techniques. You will also be evaluated as to
the respect that you show delicate instruments, the safe handling and disposal
of chemicals, the neatness of your work area and adherence to all safety regulations.
Safety:
Please adhere strictly to all safety precautions as outlined by myself and/or
your lab text. Make yourself aware of the location of emergency equipment located
in the lab, and know how to use each item. Consider every chemical that you
handle to be, at the very least, toxic! Read each label carefully. Rubber gloves
should be wore when dispensing chemicals. Be assured that violation of any safety
regulation, especially the consistent failure to wear safety goggles AT ALL
TIMES in the lab, may result in your immediate expulsion from the lab, and an
assigned grade of zero for that experiment. Any chemistry faculty member may
expel you from lab for not strictly following safety regulations.
Recitation:
The first 20-30 minutes of each session will be devoted to a recitation
period. Class will meet in its assigned recitation room to review any
previous experiment, and to discuss the scheduled experiment for that day. Students
are expected to be prepared for lab. If there are no student questions, the
class will proceed immediately to lab.
Laboratory Notebook and Reports:
Each student is required to have a sturdy, bound laboratory notebook with duplicate
numbered pages. Upon obtaining your notebook, print your name, starting date,
course and laboratory section on the front cover. Reserve the first page for
a Table of Contents, and start each new experiment on a new page. The notebook
will serve as an original record of everything that you observe during the experiment.
The white pages will serve as the laboratory report and the yellow pages as
your copy. The notebook should be organized in such a manner that another person
reading it would be able to easily reproduce all of the steps that you performed
in the experiment.
Laboratory Schedule for the fall
semester, 2003
The following items should be recorded in
your notebook before coming to lab in approximately the order indicated below:
(1) Date experiment is performed
(2) Complete title of the experiment
(3) Experiment number
(4) Brief statement of objectives
(5) All balanced equations using structural formulas, not molecular
formulas
(6) An organized table listing the identity and physical properties of reagents
to be used (main reactants and solvents) including molecular weight, melting
point (for solids) or boiling point (for liquids), density or specific gravity
(for liquids) and concentration (where applicable).
The following items should be recorded
in your notebook during lab:
(7) An organized data table listing the identities and actual amounts
of reagents used in grams or milliliters, and a listing of the number of moles
used for all reactants.
(8) All observations, as they are made. This should consist of a complete,
coherent record of every step that you perform in the experiment, followed by
anything
that you may have observed. This may include such things as the initiation of
reflux, the observation of distillation temperature(s), the formation of two
or more liquid layers, any signs of reaction such as temperature change, gas
evolution, color changes, precipitation, violent reactions or anything unexpected.
Any variations from the directions in the manual should also be noted. In short,
write in complete sentences, everything that you do and everything that you
observe.
(9) Results, including observed melting or boiling points (distillation
temperature), actual yield, theoretical yield and percent yield should be tabulated.
All calculations
should be shown. Note: Product yield and purity will be included, where
appropriate, as part of the lab report grade.
(10) Your signature at the bottom of each page, along with my initials
as witness, should be completed before you leave lab.
At this point, you will have about 80% of your report completed. The following
items should be added to your report before submitting it for grading:
(11) A discussion (one-half to three-fourths page) of the experiment
paying particular attention to an explanation of why each procedure or technique
was used, e.g.
the organic layer was washed with 5% sodium bicarbonate in order to remove
any acidic contaminants, or the organic layer was treated with
saturated NaCl in order to salt-out (remove) any water. It is not necessary
to repeat items covered in the supplemental questions.
A brief discussion of your observed results and any non-human sources of error
should also be included, e.g. the observed melting point of my product
was
140-146 compared to the literature value of 152-154. This difference may be
due to the presence of byproduct (speculate on what it may be) and/or incomplete
drying. "The observed 30% yield reflects a significant amount of
unreacted starting material (name) and the formation of significant byproduct
(name if possible). The yield may be increased by
"
(12) Supplementary questions for each experiment will be assigned at
the end of each recitation period. These should be answered, and included as
the very last part
of the laboratory report. These can constitute up to 30% of the report grade.
A discussion of the laboratory notebook is found on pages 9-11 of the lab text.
All work must be done neatly, and in ink, with no scribbles, erasures or white-out
(draw a single line through mistakes). Gross errors in spelling or grammar will
be penalized on the report. Illegible or sloppily submitted reports will be
returned to you for resubmission with a 10% penalty. IMPORTANT: Make sure that
you write legibly and that you press hard when writing so the duplicate copy
will be legible.
All work in the lab is to be performed in pairs, unless otherwise instructed.
The report is considered officially due during the next scheduled laboratory
period following completion of the experiment. 10% of the maximum attainable
grade will be deducted from the report for each week late. No reports will be
accepted after the last scheduled lab period.
Grade breakdown:
(1) Lab Reports 90%
(2) Lab Technique 10%
Any missed lab may not be made-up as a matter of course. Only reasonable excuses
for absence will be accepted. If permission is given to make up work, that work
should be made-up within one week of the time the work was scheduled to be done.
A passing laboratory grade is necessary
to pass Chemistry 201 and/or 202!
Check-in:
At the beginning of each semester, you and your lab partner will be assigned
a locker. This locker will be used by only yourself and your partner. The locker
will contain the common laboratory equipment necessary to perform most experiments,
including an expensive ground glass kit. On the first day of lab, you will be
asked to check the contents of your locker and kit against a master list. Any
missing or broken items may be replaced at no charge on the day of check-in
only. After this day, missing or broken equipment can only be replaced by using
your breakage card(s) at the stockroom. At the end of the semester (check-out),
any unused portion of your breakage card will be refunded to you. At the end
of each lab, please make certain that you clean up all of the equipment that
you used and return them to your locker. Lock the drawers and return the locker
key to the board assigned to your section.