Lab outline 2 chem PDF

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lab 2 outline...

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Procedure Outline:  Known samples being used: aspirin (ASP), acetaminophen (ACET)  Caffeine (CAFF)  PART 1 is unknown sample preparation  Choose 2 unknowns  Make 1% solution of each unknown  To do this use the tip of micro spatula to take small amount of pre-crushed tablets and add it to your 1 dram vial (small test tube)  Add several drops of ethanol  NOT ALL OF IT WILL DISSOLVE  Label the unknowns  3 known compounds will already be made  Preparing and spotting the TLC plate:  SHINY SIDE IS NOT SPOTTED  Lightly draw a pencil line about 1cm from the end of the plate  Mark 3 spots along this line where im spotting my samples  LABEL THIS WAY:  PLATE 1- 2 of the 3 known compounds (ASP, ACET) AND 1 unknown  PLATE 2 – same 2 known from plate 1 plus the second unknown  PLATE 3 – both unknown from plate 1 and 2 along with CAFF  To apply spots dip microcapillary into the sample  Make each spot as small as possible  DO NOT hold spotter to plate, just tap a few times and immediately release  Use UV lamp to see size of spots  Rinse spotter with acetone between each use (HAVE ACETONE NEARBY)  Development : chamber is a small screw capped jar w filter paper placed in it  Place 4mL of ethyl acetate into chamber  Check procedure paper  Calculate Rf values  PART 2 prepare 2 identical plates spotted with anthracene, benzil, and triphenylmethanol  Develop 1 in ethyl acetate and the other mixture in 95% hexane and 5% t-butyl methyl ether  Calculate Rf values, and in the post lab write up discuss the effect of solvent on Rf  Take pics of these TLC plates TODAYS LAB : Unknown 1&2...