All experimental work consists of preliminary planning, carrying out the experiment, keeping a record of the observations and results, and finally evaluating and reporting the results. Your lab notebook is like a diary of your experiments. It is important to keep a good notebook, as you will refer to it when writing your lab reports and when taking the lab quizzes.
The notebook must be bound (no spiral bound or loose-leaf notebooks allowed). The most useful types have pages with a grid or lines. It is recommended to use a notebook with carbonless copying—each page is doubled so that a copy of your work is made, with one page perforated for easy removal. Only pages designed for removal should be torn out. Always write in ink in your notebook so that the data cannot be altered. Water insoluble ink is highly recommended. If you make a mistake, put a neat line through the error and record the correct information. This allows referral back to the data if it turns out to be useful later. Make a brief note about why you made the change. Removal of pages from notebooks or altering of data with whiteout is viewed as fraud in the context of laboratory research.
Organize your notebook. Write your name on the front cover and inside the cover. If page numbers are not already present, number all pages in the notebook before writing anything else in them. Leave the first few pages blank for a Table of Contents. Enter experiment titles and page numbers in this table as you do each experiment. Start each experiment on a new page, leaving a few blank pages at the end of the previous experiment if you still have work to do on it. Avoid running experiments together in your notebook. As long as they are properly labeled, you may mix pre-lab lecture notes with experiments in your notebook, or you may wish to take the lecture notes at the end of the notebook in a separate section. If you have unused pages once your work is completed, write in large print “This page intentionally left blank” so it is clear that no data has been omitted deliberately.
Organize yourself by doing the preliminary write up for each experiment. Plan your work before you come to lab so that you can utilize the lab period most efficiently; for example, using "dead time" while your reaction is heating for other procedures. Each experiment will be recorded in your notebook in labeled sections as noted below. This will constitute an informal “report” of the experiment.
The originality of the notebook content is vital to the integrity of you as a scientist. (See lab policy in syllabus for explanation of the word original.) All sources used for pictures, diagrams, or physical data should be properly referenced. You may not photocopy material from the lab text into your notebook, with the exception of apparatus diagrams (no captions) and spectral reference tables. Any plagiarism issues in your notebook will be treated as dishonest academic conduct (see syllabus). Do not copy material from other students. Small portions of text may be cited from legitimate resources, if a proper citation is used.
**Before you come to lab each week, read the lab textbook pages found in your syllabus AND any Techniques (in the green TOC textbook) listed before the procedure section of the experiment. Note from the syllabus whether we will be following the miniscale or the microscale procedures. Then prepare your notebook using these sections. A formal typed-report will have these same sections that are found underlined.
1. Write the Title of the experiment on a new right-hand page of your notebook. Give the appropriate reference (e.g. Mohrig lab book, page 59). Enter the title and notebook page number for the experiment in your table of contents.
2. The Purpose of your experiment should be summarized in a few sentences. Although the purpose is short it is still important, as all scientific experiments are designed to answer a specific question or questions. You must determine what that question is and phrase it as a concise, passive-voice statement. You should also give the name of the methods (techniques) used to accomplish the purpose. “Caffeine will be isolated from tea by extraction …” is much better than “We will learn how to get caffeine… " or “I will isolate caffeine … ".
3. Make a table of the structures and appropriate physical data of compounds used, prepared and isolated. Include the molecular weight, boiling and/or melting point for each reactant and product, densities for liquids, and concentrations for solutions. These values are referred to as literature values or theoretical values. Information on using physical data handbooks appears on pages 27-31 (Technique 4) and Appendix (p. A-1) of TOC. You need to include data for solvents and reagents, not just the reactants and products. This information can also be found on the web; for example, Material Safety Data Sheets (MSDS) provide a wealth of information that includes physical properties and safe handling of the substance. Chemfinder.com also is a great source of information. The Aldrich catalog and CRC index will be available at all times in the laboratory.
4. For lab experiments that involve the preparation of a substance (a synthesis), include a balanced structure-equation for the reaction that is to be performed. If a series of reactions is used to prepare a substance, include all of them. Reactions that produce multiple products or by-products can be problematic: in some cases, an unbalanced equation with major and minor products should be written with the reaction stoichiometry clearly explained underneath.
5. Write your Procedure. A useful method is to first draw a vertical line in your notebook to divide the page into two columns, making the line about two-thirds of the way from the left hand edge of the paper. Use the wider column on the left to write a detailed list of the steps you will follow in the laboratory in your own words. This can be in complete sentences, written as a list of instructions, or whatever works best for you. Remember that a picture is worth a thousand words when trying to describe lab set-ups. You should write your procedure so that you do not have to look at your textbook while performing the experiment. The blank right hand column will be used during the lab to write procedural changes, observations and data. Before beginning the experiment, you may want to write down blank lines on which to record certain numerical data. In a formal typed-report, the procedure section will stand alone, without the second column.
6. Prepare a table for your results section now so that you know exactly what is required during the laboratory. In many cases, organic labs do not involve recording an extensive amount of numerical data; this can often lead to a difficulty in finding the one or two important numbers that constitute the final result. When a result table is clearly separated from other parts of the experiment, you will know what values to record and share with your partner before you leave lab each week.
**During your experimental work each week you should complete these notebook sections.
1. Write the date on which you are performing the experiment and the name(s) of your lab partners at the top of the right hand column of your procedure section. If you complete the lab on a different date, make sure that you write in that date next to the appropriate part of the procedure.
2. Use the right hand column of your Procedure section to record all data and observations that you are asked to record or that you think might be important. Also use this space to note any changes or additions to the procedure. Try to record the data as close as possible to the corresponding part of the procedure. If you are not sure whether or not to write down a given observation or piece of data, remember that another student in the class should be able to repeat the procedure exactly as you performed it by referring only to your notebook. To avoid deductions, write this information only in your notebook, rather than on your hand, paper towels or the lab bench. Each person is expected to have a complete set of data in his/her notebook; this way you won't be out of luck if your lab partner suddenly drops or “flakes”.
Some examples of data and observations are reagent amounts used, even if you use the amount in the lab book; time and temperature of heating, cooling, or reaction; changes in color or temperature during reaction; general appearance observed during a reaction; actual (experimental) boiling points during distillations; approximate amounts of solvents or drying agents used; amount of product obtained or isolated (both crude and purified, when appropriate); physical characterization of the substance produced or isolated (appearance, melting or boiling point reported as ranges, any chemical tests or spectrometric data); the look on your partner's face when informed that you just dropped the reaction on the floor, etc.
3. More extensive data that won't fit neatly in the right column of the procedure section should be recorded below the procedure section. This may include spectral printouts, chromatograms, or other tabular numeric data. Outside pieces of paper that are included in your notebook should be attached with tape, staples, or glue-stick. Formal typed-reports will have a distinct Data and Observations section.
4. Before you leave the lab, make sure that your instructor checks and signs (or stamps) your notebook.
**After the experiment is finished, quickly complete these sections:
1. Perform any necessary Calculations, including calculation of theoretical and percent yields for synthesis experiments, Rf values for thin layer chromatography, and percent composition of a mixture from gas chromatography. Show your work in this section. Make sure that you show the final result(s) in this calculations section, as well as in the results section.
2. When appropriate, provide Spectral Analyis of the information obtained from spectra and chromatographs. This section should include the meaning of the spectrum or chromatogram, and a summary table when appropriate.
3. Complete the Results section for your experiment with all the required numbers. Then, simply state whether or not you achieved the goal(s) set forth in your Purpose. This can be by completing the numerical table you made before lab and/or by writing one or two sentences that simply state the result. For example, "Cyclopentene was obtained in 86% yield from cyclopentanol using the procedures described …”
4. Write the Conclusion section. This is the most important part of your notebook and formal typed-report. Whether or not your experiment worked as planned, you must justify the result you just wrote (see #3) by summarizing and clarifying the physical, chemical, and instrumental data you obtained. (Is it the product you expected? Why are you sure?) For example, “The product contained a carbon-carbon double bond based on the infrared spectrum; in addition, a positive bromine test was obtained, verifying this conclusion. The infrared spectrum further indicated the absence of the cyclopentanol starting material, as there was no O-H stretch in the IR spectrum. Furthermore, the boiling point observed was within 5Ż of the theoretical value of…"
Also in this section, make comments about how effectively you were able to follow the planned procedure. You must explain how mistakes made affected the outcome, and why deliberate procedural modifications were made during the lab and their effect your result. If you failed to obtain product or only got a miserable yield, try to explain why. Indicate any procedural modifications that could help future experimenters, remembering that increasing the reactants ten-fold is not an option in a microscale experiment. Remember to write this section from the view of the experiment, not the experimenter. It is not appropriate to write "I learned to perform extractions and had a wonderful and fulfilling experience."
Separate the various conclusions into paragraphs for ease in reading.
5. Look over the Questions from the lab text. It is appropriate (but not required) to answer them in your notebook and use them during lab quizzes. You may also wish to visit office hours to get a clearer answer to these questions.