The University of Lethbridge
Department of Chemistry & Biochemistry
Chemistry 2740 Laboratory
Introduction
Notes for the Laboratory Rotation Schedule:
1.
The experiments are divided into two blocks (I and II).
2.
Your designated group letter will determine the order and the week in which
you must complete the experiments (refer to the Laboratory Schedule for
Spring 2010).
3.
Each student will be required to submit one formal report and 2 short reports
for each block (refer to the Laboratory Schedule for Spring 2010).
Unless otherwise indicated by your instructor, all reports
are due by 4:00 p.m. one week after the completion of the
experiment.
Reports are to be submitted into the designated slot in the
locked cabinet located outside the physical chemistry lab
(E760).
Reports found to be in violation of any academic offenses
will be dealt with in accordance with the Student Discipline
Policy in the most current University of Lethbridge
Calendar.
Instructor:
Wayne Lippa
Office: E784
Phone: 329-2043
Email: lippwk@uleth.ca
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Chemistry 2740 Laboratory
Introduction
INTRODUCTION
GENERAL COMMENTS:
WHMIS Certification
Students taking Chemistry 2740 lab must be WHMIS-certified. You will be
required to show your certificate proving that you passed the U of L WHMIS course
before you will be allowed to begin experimental work in the lab. Students not
WHMIS-certified must contact Carolin Cattoi-Demkiw in the Safety and Risk
Management Office (phone: 329-2350; email: carolin.cattoidemkiw@uleth.ca) to
arrange to take the online WHMIS course before your first scheduled lab of
experimental work.
Laboratory Grading
The laboratory component of Chemistry 2740 is worth 30% of the overall Chemistry
2740 course mark and must be passed in order to pass the course. A
minimum of 15/30 is required to pass the laboratory. Your final grade will be
assessed based on your results, submitted reports, laboratory techniques, and your
laboratory notebook. The laboratory portion of Chemistry 2740 consists of a series
of six 3-hour laboratory experiments. The experiments are grouped into 2 blocks of
three, and for each block two short and one formal laboratory reports are required.
It is the students' responsibility to insure the correct report format (short/formal) is
submitted; refer to the laboratory rotation schedule. You will work with a
laboratory partner (where possible). Each group (pair of partners) will perform a
different experiment than the other groups on any given day, and will progress
through each of the six experiments according to the laboratory rotation schedule.
It is imperative to you, your partner and your instructor's sanity that you stay in
your rotation. Every effort will be made to accommodate you in the event of an
unavoidable absence but there are no guarantees; the result could be a failing
grade for the missed assignment(s).
Laboratory Reports
Each person must submit an independent laboratory report for each
experiment; reports that are virtually identical to another student’s report will be
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Chemistry 2740 Laboratory
Introduction
considered to be plagiarized and will be dealt with in accordance with the Student
Discipline Policy in the most current U of L Calendar. The text for each report is to
be computer-generated. The task of preparing graphs, data and results tables will
be expedited using a good spreadsheet package. Most spreadsheet software should
have the capability to determine the best-fit line for your data. Information on the
format of the short/formal reports is given in Appendix D of this manual. In
general, reports should be clear and concise, that is, they should be as short as
possible while still being complete. Lengthy and wordy reports do not impress
those who have to read them. Examples of a short and formal report are
included in Appendix D. Notice that even though a completed description of the
experimental procedure is not given, there is enough information presented to give
the reader a basic idea of how the experiment was performed.
Laboratory Notebook
A neat, organized data book is essential to a chemist performing experiments.
Please use a hardcover notebook to record all experimental data, observations,
sample calculations and basically as much as you deem necessary to complete the
required task. The book should be fully bound (i.e. no loose pages), and the pages
numbered consecutively with a table of contents at the beginning. The data book is
a permanent record of one’s work, and as such all data when obtained should
be written in ink in the data booklet. DO NOT write data on loose pieces
of paper; these may be confiscated and destroyed by the instructor at any
time. Any mistakes should be crossed out and the correction written above the part
crossed out. Experiments should be titled, and the date(s) they were performed
should be indicated. Any pre-lab calculations and data tables can be entered into
the data booklet before you come to the lab. Doing this will not only give you an
idea of what to do and what measurements to take in the lab, it also helps you to be
more efficient with your time. The lab notebook may be checked or collected
periodically for grading and must be submitted at the end of the semester.
Laboratory Etiquette
The equipment, glassware, reagents and most stock solution of reagents will
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Chemistry 2740 Laboratory
Introduction
already be assembled at a station reserved for that experiment in the physical
chemistry laboratory (E760).
Many of the experiments require the use of
thermostated water baths; these have been calibrated and adjusted for you. Please
do not adjust them even if the thermometer indicates an error in the temperature.
If a significant deviation from the expected temperature for a thermostated water
bath is observed please alert your instructor immediately. Do not attempt to
adjust the temperature.
Techniques
Upon completion of an experiment, it is required of you and your lab partner to
leave the glassware clean and ready for use by the next group to do the experiment.
In particular, glassware should be rinsed clean and given a final rinse with distilled
water and left to dry. All transfer pipets should be left completely cleaned,
rinsed with acetone and air dried before you leave the work area. Failure to
leave the glassware clean and ready for use will lead to delays for the group that
follows, and will result in the loss of technique marks from the reports of both
members of the group that did not properly clean the glassware.
To obtain aliquots of stock solutions, pour the stock into a clean dry labeled
container, and then pipet the required amount. Avoid waste of stock solution by
pouring out only what you need. To maintain the integrity of the stock solutions
never return the excess chemicals or solution to the stock bottles and never place
pipets or anything into the stock solutions. This should also help to minimize the
wastes that are released to the sewage system. Students failing to follow
proper lab etiquette and safety procedures will lose technique marks.
Chemical Waste
Care must be exercised in the disposal of chemical wastes. In the experiments,
aqueous wastes that contain various ionic species are generated, and in some
experiments organic species are generated. In all cases the ionic species are nontoxic and, after neutralization of any acids or bases that are also present, can be
disposed of in the sewer system (i.e. down the sink). The following ions are
considered non-toxic and, in the relatively small quantities that are generated in
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Chemistry 2740 Laboratory
Introduction
laboratories, can be disposed of in the sewer system: Li+, Na+, K+, Mg2+, Ca2+,
Zn2+, Cl-, Br-, I-, PO43-, SO42-, SO32-, and OCN-, plus others. Disposal in this
manner should only be done for relatively small amounts of materials in dilute
solutions.
Organic wastes that will also be generated may include aqueous solutions of
acetone, saligenin, o-nitrophenolate, and acetic acid. Again, dilute aqueous
solutions of these organic compounds can be released to the sewage system where
they should be broken down by the bacteria of the secondary sewage treatment
plant.
The waste from each of these laboratory experiments is to be collected separately in
the containers provided. It will then be neutralized with either acid or base, diluted
with water and released into the sewage system.
Students Re-taking the Course
Students who are re-taking Chemistry 2740 within 2 years of the first time they
took it may waive the lab and use their previous lab mark if that previous lab
mark was at least 70%. Students who took Chemistry 2740 more than 2 years
ago and/or whose previous lab mark was less than 70% must re-take the lab along
with the lecture.
Laboratory Safety Rules
1.
All students in the Chemistry 2740 lab must be WHMIS certified from the
University of Lethbridge. You will be asked to show your WHMIS certificate
during the first lab period. Students who are not WHMIS certified must
contact Carolin Cattoi-Demkiw (email: carolin.cattoidemkiw@uleth.ca; phone:
329 – 2350) in the Safety and Risk Management Office to make arrangements
to complete the on-line WHMIS certification course. This course must be
passed before your first lab period.
2.
Prescription glasses or safety glasses must be worn at all times in the
laboratory. Contact lenses must not be worn in the laboratory.
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Chemistry 2740 Laboratory
Introduction
3.
A laboratory coat must be worn while working in the laboratory.
4.
Use a pipette bulb when pipetting: never use your mouth.
5.
Know the location and use of the fire extinguisher and safety showers. In E760
the extinguishers are located at the entrance, an overhead safety shower is
located next to the fumehood, and the pull-out facial shower is located by the
sink. In case of an emergency, STUDENT HEALTH SERVICES are
located at SU-020 (Phone #: 329-2484; after hours call 329-2345).
6.
Please do not bring unneeded books or clothing to the laboratory. There is
nowhere in the laboratory for storing them.
7.
To avoid possible ingestion of chemicals, do not eat or drink in the laboratory.
Also, for your own safety never taste chemicals or solutions.
8.
Dispose of chemical wastes in the appropriate containers that have been
provided (refer to the Waste Disposal section for each experiment).
9.
Broken glass should be disposed of in the container reserved for that use. DO
NOT put broken glass in the garbage cans, and do not throw other
objects into the broken glass container.
10. Double distilled and deionized water (d2H2O) must be used for all
solutions whose components take part in the reaction of interest.
Solutions used for quenching reactions may be prepared using distilled water.
11. When proceeding to dilute concentrated acids or bases, always ADD the
concentrated acid or base TO water NEVER the reverse.
12. To avoid problems in the laboratory always read the label on a chemical
bottle or stock reagent twice.
13. To reduce waste avoid taking an excess of reagent. If you pour out a large
excess, never pour the excess back into the bottles.
14. You must complete and submit the safety contract (page S-1) prior to starting
the lab.
The key to working safely in the laboratory is common sense.
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