Guidelines on Writing a Good Laboratory Report

If you keep a good laboratory notebook, writing a lab report is a breeze!  Almost of all of the work has already been taken care of, and you only need to make a few format changes and digest some data.

The lab report should have the following format:


The title needs to be short and unambigously identify the experiment.  The abstract is a concise description of the purpose, methodology, and results of an experiment of series of experiments.  It should consist of a very brief (three or less sentences) statement of what was accomplished.  Summarize findings, interpretations and conclusions.

The purpose of the introduction is to add a broader perspective to the chemistry you are reporting.  It should contain a brief statement of purpose or hypothesis, establishing why you performed the experiments you did and to put your work in context relative to the existing literature.  The specific chemistry you carried out should be described using numbered equations to clarify your discussion, if necessary.  The introduction is the most difficult section of the report to write, because writing a good introduction requires knowledge of relevant literature and mastery of topics not directly relevant to the lab experiment.

This section summarizes your findings and provides an interpretation.  For example, you might talk about the kinetic data and how the plot is first or second order, but leave the mechanistic implications for the Discussion section.  Be sure to refer to data tables, spectra, or figures which will be included in your report.  Make sure that all Figures and Tables are properly labeled and numbered.  It should be obvious what are data and what are interpretations of data.

The discussion should contain your interpretation of the experimental results along with any necessary justification.  For example, based on your observations you may wish to comment on a proposed reaction mechanism or potential sources of error.  Keep in mind that sometimes no  real conclusion can be drawn from the available data (if not, explain what additional experiments could be performed).  You may also want to provide answers to some of the questions in the book which follow the experimental procedure.

This section should summarize your major results and focus on their significance.  This might be more speculative than a simple abstract and is often a place where the author considers other possible avenues of exploration or makes predictions. 

This is a detailed description of how the experiment was actually performed.  Don’t be too detailed (such as “the weighing paper was folded in half, placed on the paper and then the balance was tared…”) but be sure to include masses, moles, reaction times, yields, color change (or lack thereof), characterization data (i.e., m.p., IR/NMR peak positions), etc. Use the format established by the ACS for reporting all spectroscopic data!  You can look up this format in any current issue of Organic Letters, J. Am. Chem. Soc., or J. Org. Chem. Be sure to identify solvents (and whether/how they were purified) and/or reference compounds (footnote if necessary).  A perfect experimental will permit someone who has never seen or performed the reaction to perform it flawlessly and to know exactly what to expect as the reaction proceeds.  Your lab notebook is critical for this section, and there should not be any discrepancies between your notebook and your report!

Use the standard American Chemical Society format for references.  Extensive references to the primary literature are not required but some must be given to demonstrate that you have read and understand the original literature, not simply a summary of it in the textbook.  You should feel comfortable discussing any of the papers referenced in your report and may be called upon to do so in class or on an examination.  Do not included references that you have not personally looked up.

While “routine” spectra such as NMR are not normally reproduced in ACS Articles, you should include such data as Figures in your reports.  The Figures should be numbered and titled according to ACS standards and referenced in the lab report.  Tables should be clear, uncluttered, titled, self-explanatory and referenced in the lab report.  Never put a Figure in your report unless you are going to discuss it (note the word is “discuss” rather than “mention”).  Do not submit your original spectra with your report – submit a photocopy and keep the original data attached in your laboratory notebook.