Lab #1 Extraction and Thin Layer Chromotography

1617 WordsMar 19, 20137 Pages
Lab #1 Extraction and Thin Layer Chromatography Kaya Gaudet 6784928 January 9, 2013 Line Structure References BenzophenoneBiphenylBenzoic Acid Extraction: A process used to separate different compounds in a mixture based on their solubility in an immiscible substance. Usually an aqueous and organic phase are used. During extraction the desired compound moves one phase and leaves the unwanted substance behind. Extraction normally has to be done a few times to leave all of the impurities behind. TLC plating can be used to mark the progress of the extraction. Thin Layer Chromatography (TLC) Plating: This is a common method that is used to monitor the progress of a reaction and determine when it is complete. In our…show more content…
The blue, on the other hand, would probably not benefit form salting because it showed no affinity towards the non-polar organic compound and the increase in polarity in the water would just make it more attracted to the substance it was already in. Part B: This introduction to thin layer chromatography challenged us to identify an unknown compound by comparing it to the TLC plates of two other known compounds. Using a mixture of 2:8 ethyl acetate and hexanes gave us a mix of polar and non-polar solvent and gave more accurate results. The Rh values for our unknown matched most closely with those of benzophenone but weren't an exact match with values of 0.57 for benzophenone and 0.54 for the unknown compared to 0.78 for biphenyl and 0.59 for the unknown. In the lab questions we are asked to compare the structures and polarity of three molecules; benzophenone, biphenyl, and benzoic acid. After evaluating those it seems plausible that benzoic acid was our unknown salt because it would have a very similar polarity to benzophenone while airing on the slower/more polar side. Part C: This part just allowed us to see the effects of using an entirely polar or entirely non-polar mobile phase and measure its effectiveness. It's obvious from just glancing at the plates that there is much less obvious separation in these two mixtures and either the solvent was too polar and almost all of the compounds reached the top (ethyl acetate) or it wasn't

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