Guidelines for Lab Reports

Learning how to effectively report experimental results is extremely important in all of the sciences. Although the customary format may vary between discipline, a scientific report should be clear, concise,  and well organized and should make effective use of tables and graphs.

General Guidelines

• The report should be thorough, well written, and well organized. 
• Reports should be word-processed  and double-spaced.
• Do not ignore the need for subscripts and superscripts in chemical formulas. These are easily available in all modern word processors.
• Bonus points will be awarded to reports that use molecule drawing software to present professional-looking rather than hand-drawn reaction graphics.
• Strive to present the results in as concise a manner as possible. A page limit of 12 pages (not counting attachments) applies to all lab reports. (Please number the pages!)

• Title Page

• Give the number and title of the experiment, your name, course number and section, and the date submitted.

• Background

• Present and discuss the theories behind the experiment including the accepted mechanism for the reaction carried out.
• Also present background information on techniques used in this experiment for the first time.
• You can also use this part to provide historical perspectives on the reaction or technique and its importance.
• Make sure to state the specific purposes of the experiment.
• Do not give away any of the findings or results of the experiment. This is background. It is not an overview or abstract.

• Results Tables

• Present all of the results of the experiment in table form. 
• Always include the absolute (in g or mg) and percent yields of any products obtained and experimental vs literature values for any physical constants measured.
  
• A melting point range should be reported for every crystalline solid product.
• Also include summaries (i.e., peak listings) of any spectroscopic data (NMR, IR, MS) obtained. Do not include solvent peaks in these listings. Do include literature values when available.
  
• Only those IR absorptions diagnostic for major functional groups, and only those MS peaks used for structure assignment, should be included in the experimental section. Round off IR frequencies to the nearest 1 cm^-1 and MS peaks to the nearest 1 m/z unit. Carbon NMR peak shifts should be rounded off to the nearest 0.1 ppm except when greater precision is needed to distinguish closely spaced peaks. (These guidelines are taken verbatim from the Journal of Organic Chemistry's guidelines for authors.)
  
• Make sure to give units where required. (A well-organized table gives the units in the column headings rather than repeatedly throughout the table.)
• Make sure to observe the significant figures convention!
• Use footnotes as necessary to fill in missing details or to give definitions of abbreviations used in the table.

• Results and Discussion 

• Start by presenting key results from the results tables briefly in a non-interpretive way. Point out the most important take-home points from the table and/or any trends you would like to draw attention to.
• Then go on to explain your interpretation of these results. Your main aim is to show how they support the theories presented in the background.
• For puzzling results that do not seem to fit the theoretical expectations,, are there valid explanations for them? Are they erroneous (due to systematic experimental error) (identify the specific reason for the systematic error if you think it is present). If you can rule out systematic error then examine how the theories could be modified to accomodate the results.
• This section should include answers to the asigned questions. Make sure to explain all answers completely even if the question does not ask for an explanation. 
• Above all, make sure your answers and interpretations make sense! Do not just take a stab at interpreting the results! If uncertain, do some Internet and/or library research or ask the instructor if you are on the right track.
• For synthesis experiments always discuss:
  • Yield - Actual yield of product versus the theoretical yield (percent yields) and possible reasons for loss of yield.
  • Spectra Interpretation - Evidence for the structure of the product from NMR, IR and/or chemical tests.
  • Purity - Purity of the product as indicated by mp, bp, NMR,  etc. Identify impurities that are present if possible, explaining thoroughly the reasoning behind your conclusions.

• Summary
  

• Reiterate the main points from your results and discussion sections in very brief form. Ideally, you can boil down the experiment to four or five main conclusions, each stated in one or two sentences.
• Comment on whether the experiment was successful or not and feel free to make suggestions as to how the experiment could have been better designed or carried out.

• References

• Give sources for all literature values.

• Attachments
• Calculations - Show an example of each non-trivial calculation, including % yield calculations, should be shown. Do not include trivial calculations such as subtraction of tare weights.
• Spectra - Attach printouts of all spectra obtained. Make sure the spectra are completely labeled (name, date section number, expt number and title). All peaks should always be labeled. By labeling all solvent peaks and other expected extraneous peaks (e.g., TMS, water) you make clear what they are without unnecessarily devoting lab report discussion to them.

• Product Submission

• Products are to be turned in for grading and recycling, All products turned in need to be completely labeled with compound name and structure, your name, expt #, and course #.
• Solid products should be submitted in small 2"x2" zip-lock baggies.
• Liquid products should be submitted in a screw-top vial. (Not a conical vial or reaction flask!)

Team Contribution Surveys (TCSs)

• These are made available on D2L shortly after the due date for the lab. TCS surveys are normally are due within one week of the lab report submission.