CHEMISTRY QUESTION

Introduction: A short paragraph stating the goal of the current experiment and the general methods/procedures that will be used to complete the goal and analyze the results. (For example, “The purpose of this experiment is to synthesize trans–stilbene using a Wittig reaction. The identity and purity of the product will be evaluated using melting point experiments.”)

Theory: One or more paragraphs describing the theory behind the experiment. Usually, that will be an explanation of the chemistry occurring ON THE MOLECULAR LEVEL. In the Acid–Base Separation and Substitution Reaction experiments, this will be a brief review of the mechanism of the reaction you are running. This is the part of your report that answers the question “Why is this happening?” Your textbook will prove to be a very useful tool when writing this portion of your report.

Mechanism: Provide the mechanism for the reaction(s) in your experiment. If the experiment does not utilize chemical reactions you may omit this section (The only two laboratory that utilizes a chemical reaction this semester are the Acid–Base Separation and Substitution Reaction Experiments). There are a few different ways to include drawings in your report. You can 1) leave a blank space and draw by hand,
2) draw by hand on another page, take a picture, and import the picture. The mechanism does not count towards your 3 page maximum limit.

Results: Depending on the particular experiment, this could be a data table or a sentence. In most cases, you will be exploring techniques, so a data table will be the most appropriate format. Make sure you include all the data you recorded! DO NOT INCLUDE DETAILS FROM THE PROCEDURE. The result section does not count towards your 3 page maximum limit.

Discussion: One or more paragraphs where you analyze your data. Begin with an overview and a brief statement of the goals of the experiment. As you discuss what happened and why, relate your discussion
to the goals of the experiment. If you have synthesized a compound, how do you know its identity and purity? What proof do you have for the latter two? What is your percent recovery or percent yield? How do your results compare to literature values (melting point, boiling point, spectroscopic data, etc.)? If you have isolated a compound, how do you know how pure it is? If you did a reactivity trend, you need to tie back the results to the theory and explain why they make sense (or not). In discussing identity:
• Since most chemicals in the organic lab look the same, how do you know your product is what you think it is? How do its measured properties compare to those in the literature? If you mention literature properties (i.e. melting point, refractive index), cite the numbers.
• Consider the IR and/or NMR spectra you obtained for your product. Do you see all the significant peaks that you would expect to see for the compound you think you have?
• How do you know you don’t just have starting material? Can you tell? In discussing purity:
• What information do you have regarding the presence on any impurities? If there are impurities present, can you tell what they are?

• Consider how you did the experiment and what impurities may still be present in the final product. Can you tell what possible impurities are not present, either through characterization of your product or through consideration of the procedure?

• Again, consider the spectra and measured properties of your product. Are there peaks present that cannot be assigned to the expected product? If so, can you tell what might be causing them?

• Is it possible that impurities are present that you can’t detect? In discussing quantity:
Consider what information you have regarding how much product you should expect:
• If the experiment is an isolation procedure, you have to calculate a percent recovery.
• If it’s a synthesis experiment, you have calculated a theoretical yield.
If you don’t end up with as much material as you expected:
• Did you not make the stuff in the first place? Explain why.
• Did you make the stuff and lose it somewhere along the way? Explain how.
Sources of Error: A few sentences on what did or might have gone wrong in the experiment. If your
percent recovery or percent yield is low, why may that be? Was there a major side reaction that impeded
good results, or was a procedural step not efficient? Focus on the chemistry – AVOID TALKING
ABOUT MECHANICAL ERRORS SUCH AS SCRAPING ALL THE SOLID FROM THE SIDES OF
THE CONTAINERS OR SPILLING THINGS. Only mention the latter if that was a MAJOR source of
error.
Conclusion and Future Experiments: A short paragraph SUMMARIZING your results and their meaning, summarizing the connection of your results to theory, describing what you think needs to be done in order for this experiment to be complete. Proof of identity and purity are usually issues to consider; how certain are you that the technique you used is 100% accurate; what other technique can you use instead or in addition. What future experiments would you propose? (i.e. what would you change to make the experiment better, can you take the techniques learned in this experiment and apply them to a different experiment?)

Finally, please include whatever spectra and graphs you have with your report. Make sure they are labeled so that it is clear who they belong to and what they are spectra of. The spectra and graphs do not count towards your 3 page maximum limit