EXPERIMENT: THIN LAYER CHROMATOGRAPHY Name _______________________________________ Instructor ____________________________________ Chem ____________ Section/Color ______________ Date ________________________________________ Laboratory Questions These questions are to be completed and turned in at the beginning of the pre-lab period. PRE-LAB QUESTIONS 1. Why should the jar used to develop the TLC plates be covered? 2. Suggest a reason that TLC plates that are stored in a highly humid room result in different Rf values than plates that are stored in a dehumidified environment. Hint: Consider the structure of the layered material on the TLC plates and how that material might interact with water molecules in the air. 3. Why should the 'spots' applied to a TLC plate be kept as small as possible? 4. Even if two spots have the same Rf value, we cannot be certain that the two samples are identical compounds. Suggest a good method to confirm that the two samples are the same or not the same. 5. Why is TLC a poor technique for the analysis of low-boiling liquids? (Hint: low-boiling means high vapor pressure at room temperature)PRE-LAB WRITE-UPThis is to be completed prior to the beginning of the laboratory session.THIN LAYER CHROMATOGRAPHYLab Report 8, Pg. 313Objective:Experimental Procedure:(Draw and label glassware setup or List equipment used)Reagents: Apparatus:Safety:Teaching Assistant InitialsNAME______________________________T.A.____________________/Color_______Chem._______Sect._______Date_________IN-LAB OBSERVATIONSThis is to be completed during the laboratory period, signed by your TA, and turned in as part of the Laboratory Report.THIN LAYER CHROMATOGRAPHYLab Report 8, Pg. 314Teaching Assistant Signature(Must be signed before checking out of the laboratory)POST-LAB WRITE-UPThis is to be completed and turned in as part of the Laboratory Report.THIN LAYER CHROMATOGRAPHYLab Report 8, Pg. 315ATTACH TLC PLATE HEREAttach any printout, graph, chromatogram, spectrum, or TLC plate (data) to this report.Results and Discussion:POST-LAB WRITE-UPThis is to be completed and turned in as part of the Laboratory Report.THIN LAYER CHROMATOGRAPHYLab Report 8, Pg. 316EXPERIMENT: THIN LAYER CHROMATOGRAPHY Name _______________________________________ Instructor ____________________________________ Chem ____________ Section/Color ______________ Date ________________________________________ Laboratory Questions These questions are to be completed and turned in with the Laboratory Report. POST-LAB QUESTIONS 1. Several of the TLC plates shown below are incorrectly spotted. For each incorrectly spotted plate, indicate what is incorrect. liquid level 2. What solvent type had the highest eluting power for the analgesics analyzed in this experiment? Which solvent type had the lowest eluting power? 3. Organic compounds must exhibit what property in order to be visualized by the technique (UV light) used in this
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