SONOMA STATE UNIVERSITY
Chemistry 335A - Dale
Trowbridge
ORGANIC CHEMISTRY LABORATORY
Prior to most laboratory
experiments you will complete a pre-laboratory write-up in your laboratory
notebook and a separate pre-laboratory exercise. Much of the material in the pre-laboratory exercises will be
directly useful in doing the pre-laboratory write-up for your laboratory
notebook. The pre-laboratory exercises
are due at the beginning of the lecture on the Tuesday preceding your
laboratory. No credit will be given for
work turned in after the time it is due, but these assignments must be
completed prior to beginning your laboratory experiment.
SONOMA STATE UNIVERSITY Dale
Trowbridge
Chemistry 335A - Organic Chemistry
LABORATORY NOTEBOOK
Your laboratory notebook is primarily designed to be a
permanent record of the actual procedures you perform in your laboratory
experiments. This is the same function
that a laboratory journal performs for someone doing original research in an
academic or industrial laboratory.
While the actual write up of this type of research journal may vary
slightly from one scientist to another, the general form is quite standard and
follows the rules or suggestions set out below. Your laboratory notebook will also include a prewrite up for each
experiment which will contain information gathered from various scientific
reference works which will be useful in the course of your experiment. This first portion of your laboratory write
up must be done before you begin your experiment, and will be checked and
initialed by your instructor prior to the start of each laboratory period.
The second part of your write
up will be the journal of experimental work.
It should be complete enough to allow the experiment to be successfully
repeated by another person without the aid of any other reference
material. It is the first hand record
of your work and as such must be written in the laboratory notebook as the work
is done. It should not be done later
from your memory of the details of the work or recopied from scratch
paper. Since it is an on-the-spot
account of the work in progress it should not be confused with the formal
laboratory report which you will do later after you complete each laboratory experiment. In the prewrite up and formal laboratory
report such qualities as neatness and organization are important, but in the
research journal only completeness and accuracy are important. The form for your laboratory notebook is
given below:
1. The laboratory notebook should be
permanently bound and should include carbons.
All pages in the laboratory notebook must be numbered and pages must
never be removed from the notebook for any reason.
2. All laboratory data and observations
should go directly into the notebook.
Scratch paper, paper towels, etc. are not acceptable substitutes for the
pages of your laboratory notebook for data and observations from your
experiment.
3. All entries in your laboratory notebook
must be in ink and entries in the notebook that appear to be in error
should not be erased or otherwise obscured.
If a piece of data appears to be wrong it should be crossed out with a
single line and a brief note be added to explain the deletion.
4. The prewrite up portion of the
laboratory notebook should include the following:
a) An experiment title.
b) A brief description of the experiment.
c) Balanced equations of the main reaction
and any important side reactions for any synthetic experiment.
d) A calculation of the theoretical yield
of product expected for the product in any synthetic experiment.
e) A table of physical constants for all
reactants and products used or prepared in the experiment (referenced).
f) A table of toxicological data for
these same substances (referenced).
5. The rest of the laboratory write up for
any experiment will be a journal of your experimental data and
observations. Completeness is the most
important feature of this portion of your laboratory notebook, and any material
such as spectral data or chromatographic evidence which are acquired in doing
an experiment should be appended directly to your laboratory journal. Since it will be the copies of your
laboratory notebook which will be turned in for grading, copies of these pieces
of data must be included. Upon completion of each laboratory period, your
journal should be signed, dated and witnessed by your laboratory instructor or
teaching assistant.
SONOMA STATE
UNIVERSITY Dale
Trowbridge
Chemistry 335A -
Organic Chemistry
LABORATORY REPORT
Your formal laboratory report will be based completely on
the experimental date as reported in your laboratory notebook. Since it is a formal presentation of the
results of your laboratory experiment it should be done carefully and neatly
with an emphasis on organization. The
report should be either typed or done on the word processing program of a
computer. Chemical formulas and
drawings that you feel are necessary to your report may be done by hand,
although excellent drawing programs are available on most computers. Your laboratory reports will normally be due
one week after the completion of the laboratory. Your laboratory report should be in the form shown below:
1. A title for the experiment.
2. A presentation of data abstracted from
the journal portion of your laboratory notebook, All data relevant to your products for any synthetic experiment
should be included in this section.
This would include all physical constants such as melting point, boiling
point, and refractive index.
3. A yield calculation for the
experiment. (See percent yield in your
laboratory text.)
4. A detailed discussion of the data and
any conclusions you have for your experiment.
For example, a discussion of any spectral data obtained in the
experiment should be given in this section.
You should also include your estimate of the purity of your product with
reference to your evidence for this estimate.
You might also include any explanations you feel are appropriate to
explain such things as an abnormally low yield or relatively impure product.
Sonoma State University Due
Thursday, Feb. 5
Chemistry 335A Laboratory
Dale Trowbridge
LIBRARY EXERCISE
Discussion:
Proper
use of library resources is an essential first step in any research project,
and it is almost always a mistake to go immediately to the laboratory without
doing a proper search of the appropriate literature. Without a library search one can waste a great deal of time
trying to reinvent laboratory procedures that are already published in the
chemical literature. Also physical
constant data from the chemical literature are needed to compare materials used
or prepared in the laboratory with known values for these substances. For example, in this course you will
routinely need boiling points, melting points, refractive indices, densities, solubilities,
etc., for your starting materials and products to verify both their identity
and purity. Since these physical
constants are used during your laboratory all of this data should be in your
laboratory notebook before
you begin any experiment.
Another,
perhaps even more important reason for spending time with the chemical
literature before entering the laboratory is to gather toxicological
information on the materials you will encounter in the laboratory. Many chemical substances have significant
human toxicity, and organic compounds, as a group should be assumed to present
a toxic risk. This is due in part to
the volatility of many low molecular weight organic substances, which makes
them a potential risk through inhalation.
In general the substances you will use in this laboratory have been
chosen in part for their relatively low toxicity to minimize this risk, but the
advisability of knowing the toxicological properties of the substances with
which you will be working should be obvious.
A significant part of what you will learn in this laboratory course is
how to assess the risk presented by a chemical substance and how to take the
proper precautions to use it safely.
This
library exercise is designed to help you acquire the skill necessary to find
both the physical constant and toxicological data you will need this
semester. In this exercise there are
three types of tasks which taken together should acquaint you with both the
relevant chemical literature and the organization to the Sonoma State
University Library. These are:
1. finding appropriate literature reference sources.
2 finding data for specific compounds in these reference
works.
3 understanding the data acquired in your literature search.
EXERCISE 1-Finding appropriate
reference sources
A
large number of potentially useful references exist which can be used to
acquire data on the physical properties and toxicological hazards of chemical
substances. The list of references
given below have been picked from this large body of sources because they are
generally available in most academic and industrial laboratories and widely
recognized as standard sources of this type of information.
A. Using the Snoopy Catalog in the Sonoma
State University Library find the call number for each of the following
reference works. Note: We now have many of these
resources in electronic versions as well as in print.
1) The Merck Index
2) Toxic and Hazardous Industrial
(Chemical) Safety Manual
3) Registry of Toxic Effects of Chemical
Substances. Later version is only
available as Chembank (cd-rom). This
will be available on two workstations in the Reference area. Students do currently have access to the
earlier print edition.
4) Dictionary of Organic Compounds. Also available on cd-rom as a subset of the
title “Combined Chemical Dictionary” located on two workstations in the
Reference area.
5) Dangerous Properties of Industrial
Materials (Sax)
6) Handbook of Toxic and Hazardous
Chemicals and Carcinogens
7) The Sigma Aldrich Library of Chemical
Safety Data
8) Handbook of Chemistry and Physics
B. According to their call numbers the
reference works listed above are found in two general areas. Give one additional reference work from each
of these two section of the reference collection of the library that looks as
if it might be useful.
C. In the Snoopy Catalog, do a subject
search on industrial toxicology. Find
the title and call number of the twenty-first entry in this category.
EXERCISE
2-Finding data on compounds in the chemical literature.
Finding
specific compounds in the reference works cited above is not always an easy
task. This is particularly true for the
most commonly used and simplest substances which are frequently listed under
any of a bewildering array of different names and synonyms in the various
reference sources. These common,
nonsystematic names were in wide usage before a systematic nomenclature was
developed for organic compounds and many of these common names are still used
in preference to the systematic ones.
For example, a solvent whose systematic name is 2-propanone is used
extensively in this laboratory, but this name is almost never used in
preference to its common name, acetone.
Other synonyms for acetone are dimethyl ketone and less commonly ß-ketopropane. Both the Merck Index and the Handbook of
Chemistry and Physics give synonyms for any substances they list, and this can
help greatly in finding substances in other reference works. There are also several important registry
numbers associated with any chemical compound that can be of great use in more
complex searches. These include but are
not restricted to the Chemical Abstracts Service Registry number and the
catalog number for compounds in the NIOSH Publication titled the Registry of Toxic
Effects of Chemical Substances (see Section 1 above). Both of these registry numbers are listed in a rather
unconventional but highly useful source, the chemical sales catalog of the
Aldrich Chemical Company. The Aldrich
catalog is also available on line and is one of a large number of convenient
web sources for physical and toxicological information for organic
compounds. The URL’s for several of
these web sites are listed below:
1.
Sigma-Aldrich.com
2.
JTBaker.com/search/
3.
Chemfinder.com
4.
chemindustry.com
A. List the synonyms found in the Merck
Index for the common solvent ethyl ether.
B. Using this list of synonyms find the
name under which this substance is listed in each of the following references:
1)
The Registry of Toxic Effects of
Chemical Substances
2) The Handbook of Chemistry and Physics
3) The Aldrich Catalog
C.
1) Using the Aldrich Catalog give the CAS
and NIOSH registry numbers for this substance.
The CAS(Chemical Abstract Service) registry number has the form
[00000-00-0] where the first set of number can have anywhere from one to five
digits. The NIOSH National Industrial
Occupational Safety and Health) registry number is listed under the RTECS#.
2) The recent editions of The Registry Of
Toxic Effects of Chemical Substances no longer list compounds by their NIOSH
registry number, but the first volume of the print edition shows the location
of compounds within the set if their CAS or RTECS registry numbers are
known. Using this system, locate ethyl
ether in the NIOSH registry and give the name under which it is listed. Also give the catalog number under which it
is listed.
D. With this Library Assignment you will be
given the names of four compounds that you will use later this semester. Each student in the course will have a unique
set of compounds assigned. Give the
page number on which each of your compounds is found in each of the following
references. If one of these substances
is not listed in a particular reference put "NL" in the appropriate
box in the table provided below
|
Reference
|
Compound
1
|
Compound
2
|
Compound
3
|
|
|
CRC
Handbook
|
|
|
|
|
|
The Merck
Index
|
|
|
|
|
|
The Registry of Toxic
Effects of Chemical Substances
|
|
|
|
|
|
Dictionary
of Organic Compounds
|
|
|
|
|
|
Sax
|
|
|
|
|
E.
1.
Search the Aldrich catalog online for the compound methyl
benzoate by:
a.
chemical formula, C8H8O2.
b.
Name, methyl benzoate
c.
CAS #93.58.3
List the total number of records in
the Aldrich catalog and the number of records displayed in each of these
searches. Note: the smaller the number of records displayed, the better the
search.
2.
Attach a print out of the Material Sefety Data Sheet for
methyl benzoate from a search of the JGBaker web site.
3. Attach a
print out of the listing for one of your assigned compounds from a search of
the chemfinder.com site.
EXERCISE
3-Understanding the data in the chemical and toxicological literature.
A. Using the Registry of Toxic Effects of
Chemical Substances or the Handbook of Chemistry and Physics as your source,
write brief definitions of each of the following terms.
1) LC50
2) LCLo
3) LD50
4) TDLO
5) mp
6) bp
7) nD
8) [a]
9) d
B. Complete
the following table of physical constant data for each of your compounds.
|
Compound
|
MW
|
mp
|
bp
|
d
|
nD
|
Solubility (H2O)
|
Reference
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
C. Write a brief summary of the toxicological data for each of
your compounds.
Chembank
- Databases of Potentially Hazardous Substances
Chembank
is composed of five databases:
RTECS (updated quarterly) U.S. Dept. of
Health & Human Services
RTECS is a compendium from the National
Institute for Occupational Safety and Health (NIOSH).
OHMTADS U.S.
Environmental Protection Agency
OHMTADS (Oil and Hazardous Materials
Technical Assistance Data System), developed by the Office of Water and Waste
Management, contains data for over 1,000 chemicals.
CHRIS U.S.
Dept. of Transportation
Chemical Hazard Response Information
System March 1991 (CHRIS) information about hazardous chemicals, gathered from a
variety of sources by The United States Coast Guard.
HSDB U.S.
National Library of Medicine
Hazardous Substance Data Bank contains
information on the toxicology of over 4,200 potentially hazardous
chemicals. HSDB also carries
information about emergency handling procedures, environmental fate, human
exposure, detection methods, and regulatory requirements.
IRIS U.S.
Environmental Protection Agency
Integrated Risk Information System (IRIS)
contains summary information on over 500 chemicals related to human health risk
assessment. The records for each of
these databases differ, refer to the individual Example of Field Search guides which outline the searchable fields
for each specific databank. Printed
copies of these are kept in the Reference area, and can be found online by
typing [F3]. The search strategy is the same for each database, and is
outlined below. Examples are taken from
RTECS.
Where to find
it
Chembank can be accessed from one of two workstations located in the Reference
area.
Searching [F2] (FIND)
Free text
searching
The simplest search is a "free
text" search, in which you search for any mention of a particular chemical
substance. Example: at the
"Find" prompt, type benzene. This request will look for any mention of
this substance. This will probably
retrieve many records, and many of these might not be relevant to your
inquiry. It is a broad search, which is
useful if:
-the substance is not one about which much
has been written;
-you don't have any information yet, and
want to know how just how much is available; or
-you are interested in performing a
comprehensive search on this substance.
Limiting your
search
If many records are found, you might want
to restrict the search to a specific field. Below are examples of field searching. For complete list of searchable fields, refer to the Example of Field Search guides.
Registry
Number Searching
The most efficient way to obtain
information on a specific substance is to first obtain the registry number from
the Merck Index, Chemical Abstracts or
one of the handbooks in the Reference area which provide basic data on chemical
substances. Once you have the registry
number you can restrict your search to that particular field, Example: 94-59-7 in rn.
Prime Name
Searching
Example: benzene in pn. This search will retrieve records in which
benzene is listed in the prime name field.
To find the most specific information on a substance, add a hyphen to
the name,
Other Search
Tips
Searching directly from the Index [F5] allows you to see which
terms or keywords are used in the database and how many times each term is
used.
Use an asterisk * to truncate search terms to retrieve variant word endings. Example: Acet* retrieves records containing the terms acetyl, acetone or acetic.
Displaying
your results [F4] SHOW
Typing [F4] will display all the records found in your search. The Page Up and Page Down keys allow you to move from screen to screen, and the arrow keys allow
you to move line by line. Each record
in Chembank displays physical data and toxicity reports
on a specific substance. This
information is divided into fields. See
below for complete list of fields, and separate guide RTECS -Examples of Field Search , for further explanation of these
fields. To display only specific
fields, type O for Options, then C to change options and indicate which fields you wish to display.
Example:
Fields to
Display: ALL -------------List in this section the fields
you want to display, Example: pn, rn, at
Records to
Display: ALL ------------Type in this section all, or the number of the record(s)
Fields available in RTECS in order of their appearance (starred
(*) field is unsearchable):
