Post-lab (This is an INDIVIDUAL report)CHEM 14CL FALL 2002 Experiment #9 - Distillation and GC Guidelines Pre-lab is due at the beginning of the lab section. Refer to laboratory syllabus for the due date of the post-lab report. Pre-lab and Post-lab MUST be written inside your lab notebook (with the exception of graphs) Pre-lab (Include BOTH period 1 & 2) 1. Introduction (for the ENTIRE experiment) 2. Procedure in Flowchart Format (for the entire experiment). Make sure you reference the procedures. 3. Complete ALL the pre-lab questions under "period 1" ONLY (see page 105). NO need to complete "period 2" study question. For question #2 of period 1, you may also use the following web-site: http://chemfinder.cambridgesoft.com/ NOTE: There is NO pre-lab for the second period of the distillation lab. Post-lab (This is an INDIVIDUAL report) (I) Abstract – outline the goals of the experiment as well as the technique that you used in achieving such goal(s). Also, summarize all experimental results. (II) Record the temperature at which the first drop of condensate forms and the temperature ranges over which each of your fractions distilled. (III) Label each of your gas chromatograms as to the sample injected. Calculate the % composition of each of your fraction from gas chromatograms. Show ALL your work. (IV) Compare the retention time of the standard toluene/ethyl acetate mixture with your samples. What can you conclude? Explain. (V) Conclusion - summarize results (again) - justify the % composition results from the gas chromatograms. In other words, are they what you expected from a simple distillation technique? - Discuss how you could have achieved a better separation in the distillation.(VI) Sketch your chromatogram of your first fraction . Sketch how the chromatogram would have looked given the following conditions: (1) there had been twice as much toluene in the fraction; (2) the gc column had been twice as long; (3) the temperature of the column had been higher; (4) the chart paper advance had not been turned
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