CH 2225 LAB REPORT EXPECTATIONS

I.  Title: 

Include a brief title.

II.  Purpose/Objective:

BE SPECIFIC!  The reader should know exactly what the main goal of the lab is by reading this BRIEF statement(s).  A typical objective for a synthetic lab is as follows.

“To prepare ethylene glycol di-p­-toluenesulfonate via a nucleophilic substitution reaction involving ethylene glycol and tosyl chloride.”

III.  Chemical Equations/Reaction Mechanism/Sketch of Apparatus:   

Chemical Equations:  Include a standard chemical equation (reactants ----> products).

Reaction Mechanism:  For a synthetic experiment, include a step-by-step mechanism for all relevant reactions.  How to ensure a good grade for this section – write a complete mechanism!

Sketch:  A sketch of the main apparatus with labels for the equipment also belongs here.

IV.  Table of reagents/starting materials/products & physical properties

Take the time to neatly prepare a table that includes all reagents and solvents with which you will be working.  Include appropriate physical properties (b.p., m.p., MW, d, hazards, etc.) and safety considerations.  Get this info from either a library source or the Material Safety Data Sheets on the computer outside the chemical stockroom.

V.  Procedure/Observations: 

In this section your goal should be to NOT need your book to complete the experiment.  This means that, before class, you can either copy every word from the procedure section in the book OR summarize with detail the procedures from the book that you will use for the experiment.   I recommend the latter.  It gives you better preparation for future classes (jobs?) and will force you to really read the book and understand the experiment.  This will improve your lab efficiency and safety. 

Keep in mind that the reader should be able to perform your experiment (not the one written in the book) by reading your procedures.  This means that any modifications to the book procedure must be included in your report.  In principle, then, everyone should have a unique set of procedures as they are all working independently of one another.  Get your TA’s initials on your procedure page prior to leaving the laboratory. 

Finally, the recording of observations cannot be overemphasized.  It is through these observations that the a researcher can either determine if they are obtaining the same results as you or, if there are problems, diagnose a possible cause.  Be clear as to what specific procedure gives rise to a particular observation.  For example, don’t just report a color change, but explain what was done to elicit that change.

VI.  Results:

For a synthetic experiment, your results section should include masses of products, melting points, spectra, etc.  A percent yield must be reported WITH the supporting calculations.  Where appropriate, include a limiting reagent calculation.  Include all spectra AND summarize all spectral data in a neat, preferably tabular form. All tables should have a brief, descriptive heading.

VII.  Discussion/Conclusions

First, address your objective.  For a synthetic experiment, did you make what you planned to make?  If so, how do you know?  What supporting characterization data do you have to support your conclusion?  What is the % yield?  If possible, compare the properties of your product to that of the starting material to further convince the reader of your success (hopefully).  Interpret all data, including spectra.  Don’t make the reader sort through your spectra and/or different sections of your report to look for your interpretation.  Is your melting point close to the known value?  Is it higher or lower?  What does that tell you?  Is the m.p. range small or large?  What does that tell you?  Have you assigned all the important peaks or resonances in a particular spectrum.  What conclusions can you draw from that analysis?  Finally, include sources of error.  These are of two main types:  human error and systematic error.  Human errors are mistakes that you or your lab partner have made.  These need to be included and should be a part of your discussion section to explain a particular result that they may have caused.  Systematic errors are those that are inherent in the particular experiment.  It shows keen insight on your part to look for areas in the experiment in which error is present.  Try to come up with legitimate sources of error for each experiment.

VIII.         Questions from Text:

Answer the assigned questions from the book. 

HINTS

• Use clearly marked headings for each section.  The more organized your presentation, the happier the reader (grader!).

• Number your pages.

• Write clearly and in ink.  Mistakes are crossed out with a single line.  Look over your report before you turn it in.  Your job is to communicate.  Poor legibility, organization, etc. invariably leads to a poorer grade simply because the reader can’t understand what you have done.  Great data/conclusions can be destroyed via poor communication.  

• Show calculations.

• Interpret all spectra.

• At the risk of sounding like a parent, don’t wait to the last minute to complete your report.  That way, if you have questions, there is plenty of time to get them resolved.

• You should never be shy about asking questions.  I hope, by now, that you realize we (the TA’s and I) will answer your questions and help you to understand the mechanisms, synthetic procedures, instrumentation, spectral interpretation, etc.  Take advantage of this.

• If you ever have questions about your lab reports, contact me at any time.  I am here to help you, but you have to let me know when you need help.

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