1. Gas Chromatography of Distillate CHEM 315 Week of November 1 st, 2010 Alexis Patanarut

2. Due dates Today Distillation of a Mixture lab report - at the beginning of class – See http://classweb.gmu.edu/chemlab/sws/315/gc- rep.htm for instructions on how to go about assembling this lab report Carbon copy from your lab notebook for today's experiment - at the end of class Next week GC of Distillate lab report - at the beginning of class

3. Purpose The purpose of today's lab is to analyze the fragments you collected from your distillation last week via GC You will be comparing the results of your GC chromatographs with your line/bar graphs from last week's distillation – Do they differ? – If so, how do they differ? – What do the peaks tell you about the composition? About the efficiency of the distillation techniques?

4. Procedure Inject a sample of your unknown mixture into the GC. – You can use the retention times from the GC-acetates experiment to identify the peaks Inject the saved distillate fractions for the simple and fractional distillations Calculate the mol % composition of the unknown – Use the thermal response ratios from the GC acetates lab to calculate out the mole ratios and then the mol % composition for your unknown – Compare your results with your conclusions by graphical methods last week

5. Final notes Work in the same groups as you did for the distillation experiment – Each student should inject at least one sample into the GC After lab, each group should photocopy the gas chromatograms and distribute them among the group members