Chem 14CL Summer 02 Post-lab Report - 7(a) This is an individual report Abstract Outline the objective of the experiment as well as record any technique that you used to isolate and analyze the caffeine product. Data Analysis (1) Record all observations. (2) Use equations to help explain any chemical reactions. or explain the phenomenon (physical changes) behind each of your other observations. (3) Calculate the % yield of crude caffeine that you recovered. (4) Mass Spectrum of caffeine: (i) identify the base peak. (ii) identify the molecular ion peak. (iii) is the molecular ion peak the same as the base peak in the spectrum? (5) Calculate the Rf values for pure caffeine and your own caffeine product. (6) UV Spectrum Analysis Using Beer’s law, determine the molar extinction coefficient for your own caffeine Product at λmax 272 nm. Conclusion (1) Compare your yield to the reported value of caffeine content in tea leaves. See note. (Note that the caffeine content in tea leaves is about 2-4%). Explain any differences. (2) Compare experimental IR spectrum to literature IR spectrum. What can you conclude about the purity of your product. (3) Interpretation of caffeine product composition and purity from TLC results. Explain.Chem 14CL Summer 02 Post-lab report - 7(B) "Infrared Spectroscopy Experiment" This is a group report. (I) Completed IR worksheets for the 5 molecules. The 5 molecules are: 2 different carbon dioxide; acetic acid; propionamide and allyl benzoate. (II) Compare the vibrational frequencies and modes of carbon dioxide (read page 82-89 of the lab manual) with the ones calculated by the 2 different theoretical methods from Spartan software (i.e. PM3 and STO3G) (III) Bond angles, distances and strain energy of caffeine. (IV) Analysis of the pure caffeine spectrum (Literature Spectrum) - identify as many vibrational motions you can on the
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