CHEM 14CL FALL 2001Procedures for experiment 7(B) - see p. 82- 89 (lab manual)CHEM 14CL FALL 2001Postlab Report for experiment 7(a)This is an individual reportCHEM 14CL FALL 2001 7(A)&7(B) - EXTRACTION AND PURIFICATION OF CAFFEINE FROM TEA LEAVES You MUST turn in the prelab at the beginning of your lab section. Prelab report must be written inside the lab notebook. Procedures for experiment 7(A) - see p.76 - 80 (lab manual) Procedures for experiment 7(B) - see p. 82- 89 (lab manual) PRELAB FOR EXPERIMENT 7(A) NOTE: There is ONLY ONE PRE-LAB for 7(A) even though this is a 9-hour lab (3 lab periods). IMPORTANT: Turn in item (1) & (2) (i.e. introduction & flowchart) listed below on October 16 & 17 (depending on the day of your lab). Turn in item (3) (i.e. the study questions) on October 18 & 19. 1. Introduction 2. Prepare a flow chart of procedures AND show the location of the caffeine throughout each step of the experiment in the flow chart. (Hint: See the end of Expt 8 in Landgrebe). Make sure you also REFERENCE the procedures. NOTE: Make sure that you look for organization of ideas and not just a copy of the procedure in boxes. 3. Study Questions NOTE: TURN IN THE STUDY QUESTIONS ON OCTOBER 18 & 19. Complete questions 1,7,8,10,11 in Landgrebe (see page 140-141) (MUST SHOW ALL WORK FOR FULL CREDIT). Note: Kp is equivalent to α (see lecture guide for definition). NOTE: There is NO prelab for experiment 7(B)CHEM 14CL FALL 2001 7(A)&7(B) - EXTRACTION AND PURIFICATION OF CAFFEINE FROM TEA LEAVES Postlab report must be written inside your notebook with the exception of graphs. Refer to the lab schedule for post-lab reports due date. POSTLAB REPORT FOR EXPERIMENT 7(A) THIS IS AN INDIVIDUAL REPORT (i) Record all observations. (ii) Use equations to help explain any chemical reactions.or explain the phenomenon (physical changes)behind each of your other observations. (iii) Calculate the % caffeine that you recovered from tea. (iv) Compare your % caffeine value to the reported value of caffeine content in tea leaves in Landgrebe (see page. 380 - 381). Explain any differences. (v) Compare experimental IR spectrum to literature IR spectrum (provided with the 7(B) worksheets). What can you conclude about the purity of your product. (vi) 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? POSTLAB REPORT - 7(B) IS FOR THE “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 actual vibrational frequencies of carbon dioxide 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 - identify as many vibrational motions you can on the
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