General Guidelines
In organic chemistry lab there are generally two different kinds of experiments: the "preparative" type in which you carry out some sort of synthesis or conversion; and the "investigative" type where you study a particular laboratory technique or chemical property. The format for these two types are very similar. The main difference is that in the preparative experiment, you will have a chemical equation which shows the transformation being performed.
There is also a time phase for the various lab notebook entries. Some information needs to be entered and understood before you ever set foot in the lab. This includes things like the title, purpose, table of reagents used, and the procedure you intend to follow. During the lab experiment, you will record actual amounts of chemicals used, observations, and temperatures, etc. After the lab is over, you will need to perform various calculations and record results and conclusions. The following paragraphs describe the specific sections of the format. If you have questions, be sure to ask your lab instructor to clarify.
Pre-lab (These sections must be completed before you come to lab. If they are not done satisfactorily in the estimation of your instructor, your notebook will be annotated "NP" - not prepared - and you will lose 10% of the lab points right off the top. If there are major deficiencies, you will not be allowed to perform the lab and will received a zero for the day.)
Header Information. This includes the title of the lab, your full name and the date performed. On subsequent pages, the title may be abbreviated if it is particularly long. Include your name (last is sufficient) and date on these pages as well.
Purpose. This should be a two-three sentence summary of what you intend to accomplish. Don't blindly copy the summary that is in the lab text. Sometimes these are incomplete or have been changed.
Reference. This is a bibliographic reference to where the procedure was obtained. It should include as a minimum the full title of the lab text, the authors, the edition, and the pages used.
Table of Reagents and Products. List in tabular form the appropriate physical properties of each reactant, reagent, solvent, and product, including molecular weight, melting or boiling point, density, and other properties where applicable. The "CRC Handbook", "Merck Index", and chemical catalogues are primary sources for this information. Also note any particular hazards associated with the use of the reagents. The hazards should generally be more than single word entries such as "irritant". Irritant to what? See the example lab report for the level of detail that is expected for hazards. This information is easily found in various MSDS websites such as www.msdssearch.com. If the hazards are particularly lengthy, they could be placed in their own table. They don't have to be in a little box at the end of the row. The important thing is that you have them somewhere and that you're aware of what you're up against each lab from a health standpoint.
Chemical Reaction (for preparative labs). Give the main chemical reaction leading to the desired product. Include side products if known.
Limiting Reagent and Theoretical Yield (for preparative labs). Show calculations for LR and theoretical yield. Because most of our experiments are done on a micro scale, yields should be reported in mg.
Procedures. At this point you will divide the lab notebook into two columns. In the left-hand column you will write the steps you plan to follow to accomplish the experiment. Leave the right-hand column blank at this time. The steps may be numbered if you desire. These do not need to be complete sentences. But they need to include enough detail for you to perform the lab since you will NOT have your lab text with you. You may need to leave a line or two between steps. The right-hand column will be used to record what you actually do and all data and observations. So think about the data you will need to collect and space the steps accordingly. An example is shown later on.
During Lab
Observations and Data. When you actually perform the experiment, you will use the right-hand column to record observations and data. If the step says to "add about 1 gram of X", you will record the actual amount used to the full accuracy of the scale, for example, 0.978 g. You will also record the appearance of reactants and products, color changes, formation of precipitates, boiling point, melting points, start and stop times of refluxing, etc. Also note any deviations from your plan. You get the idea - everything that transpires during the experiment goes into the notebook. It is important that you obtain all relevant data before you leave the lab. It is a serious breach of your integrity and scientific trust to make up data that you forgot to record during lab.
Signature and Date. Every page should be signed and dated before you leave the lab for the day. Be sure to place a diagonal line through unused portions of the page and initial it. Your instructor will also initial your notebook page(s) before you leave.
After Lab
Calculations. Most labs will have some sort of calculations that need to be performed. These include things like % yield, % recovery, % error, etc. At least one complete calculation should be shown for each type required. This will allow your instructor to see where an error was made if the correct answer was not obtained.
Results and Discussion. In this section you interpret the data obtained previously. You are trying to answer the question "what does the data mean". Did you achieve the purpose of the experiment? How do you know? If you had an unknown, what was it and what was the process you used to deduce its identity? If you have product spectra from a preparative lab, does it support your expectations? If the % yield was low, try to figure out why. You can also include suggestions for improving the experiment. Avoid editorial statements like "I think the experiment went well". If you address sources of error, be specific. Don't simply allude to things like "human error".
As you can see, there is a lot that goes into the notebook for each and every experiment. Initially you may feel overwhelmed. But with a little practice and coaching, this will all become second nature. During lab lecture, we will discuss what should be in the notebook for each experiment. This is also a good time to ask questions about the notebook in general or the upcoming experiment specifically.
Some of the data you record in your lab notebook will also show up on the Datasheet for that lab. For most labs, you will turn in a datasheet along with your notebook pages. Datasheets are typed and offer a way to present your findings in a clear, concise way that is easy for your instructor to grade. (Alternatively, we could write lengthy lab reports. Yuk!). The datasheet may also have some post-lab questions for you to answer. Remember that all work you submit must be your own. You may discuss your results and datasheet questions with other students or (preferably) your instructor. But when you sit down to write the datasheet, do it completely on your own. Academic misconduct is unacceptable and will not be tolerated.