CHEM 14CL FALL 20027(A)&7(B) - Report Guidelines for EXTRACTION AND PURIFICATION OF CAFFEINE FROMTEA LEAVES EXPERIMENTYou MUST turn in the prelab at the beginning of your lab section. Prelab report must be written inside thelab 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).1. Introduction - list the goal(s) of the experiment as well as any experimental techniquesthat will be used during the experiment for purification and/or identification.2. Prepare a flow chart of procedures AND show the location of the caffeine throughout each step of theexperiment in the flow chart. 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 QuestionsComplete the following questions. (MUST SHOW ALL WORK FOR FULL CREDIT).Note: Kp is equivalent to a (refer to "Extraction of Caffeine" lecture guide for definitions and the necessaryequations to complete the study questions).(a) You wish to extract an organic compound from an aqueous phase into an organic layer (three to sixextractions on a marcoscale). With regard to minimizing the number of transfer steps, would it be better touse an organic solvent that is heavier or lighter than water? Explain.(b) A compound distributes between water (phase 1) and benzene (phase 2) with Kp = 2.7. If 1.0g of thecompound were dissolved in 100mL of water, how much compound could be extracted by THREE 10-mLportions of benzene?(c) If the value of Kp is 0.5 for the distribution of a compound between pentane (phase 2) and water (phase1), and equal volumes of the two solvents were used, how many extractions of the aqueous layer will berequired to recover at least 90% of the compound?CHEM 14CL FALL 20027(A)&7(B) - Report Guidelines for EXTRACTION AND PURIFICATION OF CAFFEINE FROMTEA LEAVES EXPERIMENTStudy Questions (Continue):(d) Calculate the % of a compound that can be removed from liquid phase 1 by using ONE to FOURextractions with a liquid phase 2. Assume that Kp = 2 and the volume of phase 2 equals to 50% that of phase1.(e) A slightly polar organic compound distributes between diethyl ether and water with a partition coefficientof 3 (in favor of the ether). What simple method can be used to increase the partition coefficient? Explain.NOTE: There is NO prelab for experiment 7(B)CHEM 14CL FALL 20027(A) - EXTRACTION AND PURIFICATION OF CAFFEINE FROM TEA LEAVESPostlab report must be written inside your notebook with the exception of graphs. Refer to the lab schedulefor post-lab reports due date.POSTLAB REPORT FOR EXPERIMENT 7(A)THIS IS AN INDIVIDUAL REPORT(A) AbstractOutline the objective of the experiment as well as any experimental results that obtained. Include anytechnique that you used in the lab to isolate, purify and analyze the experimental products.(B) Data and Data Analysis(i) Record all observations. (ii) Use equations to help explain any chemical reactions.or explain the phenomenon (physicalchanges)behind each of your other observations.(iii) Calculate the % caffeine that you recovered from tea.(iv) Mass Spectrum of caffeine: (i) identify the base peak. (ii) identify the molecular ion peak. (iii) is themolecular ion peak the same as the base peak in the spectrum? Note: You will learn about the concepts in mass spectroscopy later on this quarter. At this point, just use thefollowing definitions to answer the questions related to mass spectrum of caffeine.Base peak is the signal on the mass spectrum that has the highest intensity (or 100% on the y-axis)Molecular ion peak refers to the signal on the mass spectrum that gives you the molecular mass of thesample. Simply look at the x-axis (which is the mass) and look for a signal that gives you the molecularweight of caffeine.(v) UV Spectrum of caffeine: Calculate the molar extinction coefficient (e) for caffeine. Show all your work.Note: Assume the diameter of the cell holder to be 1 cm.Hint: Use Beer’s law to find the molar extinction coefficient(vi) Calculate the Rf values of BOTH the pure caffeine and the crude caffeine. Show all your work.Note: Read pages 697-708 in Pavia about the concepts in Thin Layer Chromatography (TLC) . Pay specialattention to pages 706-708 on how to find Rf value and what it means. I will explain TLC later on in thequarter.CHEM 14CL FALL 20027(A) - EXTRACTION AND PURIFICATION OF CAFFEINE FROM TEA LEAVESPostlab report must be written inside your notebook with the exception of graphs. Refer to the lab schedulefor post-lab reports due date.POSTLAB REPORT FOR EXPERIMENT 7(A)THIS IS AN INDIVIDUAL REPORT(C) Conclusion(i) Compare your % caffeine value to the reported value of about 2-4% caffeine content in tea leaves. Explainwhat may cause the % to be differed (i.e. where the loss of caffeine may come from during the experiments).(ii) Compare experimental IR spectrum to literature IR spectrum (provided with the experiment 7(B)worksheets). What can you conclude about the purity of your product ?(iii) Interpretation of caffeine product composition and purity from TLC results. Explain all your reasoning.Attached ALL the spectra with your post-lab report!!IMPORTANT: Before answering part (iii), refer to the notes listed for TLC earlier in the guidelines.CHEM 14CL SRPING 20037(B) - IR SPECTROSCOPYThere is no pre-lab report for this part of the assignment.The Postlab report must be written inside your notebook with the exception of graphs. Refer to the labschedule for post-lab reports due date.POSTLAB REPORT - 7(B) IS FOR THE “INFRARED SPECTROSCOPY EXPERIMENT”.THIS IS A GROUP REPORT.Your report will include the following sections:(I) Completed IR worksheets for the 5 molecules.The 5 molecules are: 2 different carbon dioxidecalculations; acetic acid; propionamide and allyl benzoate.(II) A comparison of the actual vibrational frequencies 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 andSTO3G).(III) The bond angles, distances, and strain energy of caffeine.(IV) An analysis of the LITERATURE caffeine IR
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