The Organic Chemistry Laboratory
CH 241 Organic Chemistry
Portland Community College, Sylvania Campus
The organic chemistry laboratory provides you with a unique opportunity to do the reactions you can
only read about in your lecture course. Before you begin to do a chemical reaction in the laboratory,
you must learn the techniques basic to organic chemistry research and laboratory safety skills.
You are required to maintain a laboratory notebook to document your preparation, your observations,
and your conclusions for each laboratory experiment. An accurate laboratory notebook is an essential
“living” document of the organic chemist. It is not unusual that references are made to the laboratory
notebooks years after the research has been completed. Be sure the future reader will know exactly what
you did and why and that your recorded data is consistent with your conclusions. As an example, the
laboratory notebooks belonging to Linus Pauling, a Nobel Laureate from Oregon, have recently been
posted on the web: http://osulibrary.orst.edu/specialcollections/rnb/index.html. Your laboratory
notebook for the organic chemistry class should be a complete record of all your activities in the
Organic Chemistry lab and worthy of publication on the web should you become famous some day.
Each student is required to keep an individual laboratory notebook. The notebook must be an approved
type with permanent binding and carbonless duplicate pages. All writing in the notebook must be in
either black or blue permanent ink. No pencils are allowed!! Mistakes must be single-lined out. Do
not erase, scratch out, or use white out. Write your name, class information, and date on the first page of
the laboratory notebook and reserve several pages at the beginning for a table of contents.
You are expected to work independently. It is essential to plan each lab very carefully, so you will be
prepared and know what you will be doing during the experiment.
Components of a Laboratory Notebook
http://orgchem.colorado.edu/hndbksupport/labnb/labnb.html
The following components should be listed for each experiment:
1. Name of experiment
2. Purpose of experiment (The Purpose of the experiment need only be a sentence or two that
briefly describes the experiment to be performed (including react, reagents, reaction conditions,
and product) and the purity and identity procedures that are to be utilized
3. Balanced chemical equation(s) for main reaction(s)
4. Chemical structures of main reagents
5. Reasonable stopping places and estimated time to reach stopping place
6. A table with data for major chemicals used (This allows easy review of the work performed and
calculations determined. Only include what is applicable to your experiment)
7. Waste Disposal
8. Outline of procedure (The outline should allow one to perform the experiment without the use of
the lab text; be brief, yet concise. This must be in outline form! After having prepared for the
lab, this outline should be a substitute for the lab experiment book).
Items 1 through 8 must be completed and 1-7 submitted to the Instructor for initialing
before starting the experiment. Item should be started on the next page after 7 and done
before lab starts. Items 9-12 are to be completed while in the lab or after the experiment is
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finished. The completed lab report needs to be turned in to your Instructor one week after
completing the experiment.
9. Observations
10. Analysis: This includes an IR spectrum of your product, labeled with name, solvent used and
major peaks indicative of your product, TLC Analysis, Melting or boiling point, or GC analysis.
(Please also attach a theoretical IR spectrum from an internet site and compare the two spectra)
11. Discussion of results (compare and analyze physical and spectroscopic data and comment on the
success of your experiment)
12. Conclusion
Before you come to the Lab
1. Title and Date
Give the title of the experiment and the date on which it is done.
2. Purpose/Introduction
In a sentence or two, state the purpose of the experiment.
In our organic laboratory class there are different types of experiments: technique and preparative. A
technique experiment is one in which you are performing a technique for the first time and studying its
details, for example, melting point determination, distillation or extraction. A preparative experiment is
one in which a compound is synthesized from other reagents. If the experiment is a preparative
experiment, the introduction also includes the balanced equation and mechanism for the reaction.
3. Balanced Equations
These are not necessary until we do a synthesis (Exp 6 and 7)
4. Chemical Structures
Use line diagrams and a name under/next to each structure.
5. Reasonable Stopping Places and Time Estimates
You probably won’t be very good at estimating times in the beginning. Take your best guess and learn
from that. The point of this is, if you have to leave in the middle of the experiment, at which point can
you leave and not have to start all over again. Also, this may help you manage your time.
6. Physical Data in a Table
Prepare a table that includes the MW, chemical structure, melting point, boiling point, density,
solubility, and hazards of all pertinent chemicals used in the experiment. If there are no hazards, you
don’t have to invent one. Sometimes solubility is not relevant, so it isn’t necessary to include. Also
include the purpose or functions of the chemicals used, for example, solvent, catalyst, drying agent,
extraction agent, etc. For your convenience, tables of physical data for all chemicals used in this course
are included in the Handbook of Chemical Compounds. Alternatively, you can find the information on
the Internet at www.chemfinder.com.
In a preparative experiment, record the amount of reagents in moles and grams or mL (as applicable),
determine which reagent is the limiting, and calculate the theoretical yield of the product as well as the
percent yield. Be sure to include your actual calculations for these values. The physical data are most
conveniently presented in tabular form. This allows easy review of the work performed and calculations
determined. Only include what is applicable to your experiment.
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Name of
Chemical Used
Chloroform
Molar Mass
(g/mol)
Chemical
Structure
BP (or MP)
°C
Density
g/mL
Mass or
Volume Used
Purpose
119.38
CHCl3
61.7
1.498
2.3 mL
solvent
7. Waste Disposal
Include a section for disposal of chemical waste. It is essential that you have a proper disposal plan in
place before coming to the lab. Most of the experiments will have general instructions or suggestions.
You will find a variety of labeled waste containers in the hood; organic solid waste, flammable organic
solvents, halogenated organic solvents, acetone waste. Be sure to discard all chemicals in the proper
containers. This is important so that you do not accidently throw poisonous stuff down the drain.
Procedure/Outline
Briefly summarize the procedure to be followed, preferably either as an outline or as a flow chart. You
need a brief but complete listing of what you plan to do in the lab, including reasonable stopping places
and estimated time to reach a stopping place. The first time you do a technique, such as distillation, in
the procedure section include a sketch of the apparatus and a description of how to assemble the
apparatus and how to conduct the distillation. In later experiments, it will be sufficient to state only that
the liquid was distilled.
Notebook Format
Outline
1. Transfer 2.0mL of the assigned alcohol, 2.0 mL of the
assigned carboxylic acid, and 3 drops of concentrated
sulfuric acid into a clean, dry 5-mL conical vial.
Observations
Used 2.0 mL ethyl alcohol
Used 1.9 mL benzoic acid
H2SO4
solution turned cloudy
Purification and identification of the product should be described in this section.
While in the Lab
Data and Observations
Your observations of the experiment as it progresses are important new information. Write these
observations (color changes, appearance of crystals, formation of an emulsion, boiling temperatures, test
results, etc.) in your notebook as you do the experiment. Also record the weights and/or volumes of
reagents and products and tare weights in this section. Be sure to record these amounts with the correct
number of significant figures. Never record these values on slips of paper. Always post them directly
into your laboratory notebook.
Any changes made to the experiment should be included in the observation section. In general, you do
not need to re-write the “procedure” section; instead, you may state that “the procedure was carried out
as planned” or “the procedure was carried out as planned except….” At times, however, you may have
to write the procedure out partially. For instance, if you state, “the solution turned green,” you will have
to write out enough of the procedure so that the reader will know at what step the solution turned green.
As a guideline, consider that from the procedure and data and observation section, any chemist should
be able to duplicate your experiment. With this in mind, be thorough but include only pertinent
information.
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Chemical and Instrumental Supplies
A supply cart will contain all necessary chemicals and additional equipment labeled properly with the
experiment number. Always return chemicals after you have used them to their proper place.
Always handle equipment and chemicals in a safe manner.
Postlaboratory Analysis
Discussion/Analysis of Your Results
The discussion of your report is probably the most important part of your lab. This is the section in
which you interpret the data obtained in the previous section. For instance, indicate the amount of
purified compound that you obtained and how the purity and identity of the compound was assessed. If
applicable, record the number and identity of an unknown. In a preparative experiment, state the percent
yield. Include and discuss instrument printouts, such as TLC and experimental IR spectra. A reference
IR spectrum from the library or the Internet should be included and compared to the experimental IR.
Discuss any changes that you have made to the experiment and how these have affected your outcome.
For example, discuss any unusual low/high yields in a preparative experiment and then evaluate what
errors may have led to the observed disagreement. Likewise, in a technique experiment, discuss any
difficulties you may have encountered and anything that you would do different if you were to perform
the experiment again.
Conclusion
The conclusion is a summary of your results, not your experimental procedure. Explain any relevant
experimental difficulties or changes in the procedure and comment their probable effect upon the data
postulated. State if the experiment has provided the necessary outcome that was expected and briefly
comment on what you have learned from the experiment. If the experiment was a synthesis, comment
on your yield and purity.
Post lab questions These are written here, after the conclusion, so that I can easily find them.
Grading
From reading the above you probably have noticed that your notebook becomes an essential part of your
organic laboratory. Carbon copies of your finished experiment will be collected for grading one week
after completion of the experiment. In addition to regular submission of a copy of your laboratory writeup, the complete laboratory notebook will be collected at the end of term.
Your work in the laboratory will be assessed in a number of ways; your grades on the lab write-ups (20
pts each), your grades on the formal lab report (25 pts), your grade on the complete laboratory notebook
(20 pts), your preparedness for the lab, and your laboratory conduct, (correct waste disposal, care of
laboratory instruments, and laboratory safety – points deducted from lab reports) for a total of 225 pts.
It is understood that all data are obtained and analyzed by the experiment. Dishonesty will not be
tolerated.
Lab Write-ups are to be turned in the next week after completing the experiment. Points
will be deducted from late reports.
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