Caffeine Post-lab - University of California, Los Angeles CHEM 14CL
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CHEM 14CL
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CHEM 14CL
CHEM 14 CL
10(A) – CAFFEINE EXTRACTION AND PURIFICATION AND CHARACTERIZATION FROM
“ALERTNESS AID” TABLETS Post-Lab
(A) Abstract
Outline the objective of the experiment as well as any experimental results that obtained. Include any
technique that you used in the lab to isolate, purify and...
caffeine extraction and purification and characterization from “alertness aid” tablets post lab
chem 14 cl 10a – caffeine extraction and purification and characterization from “alertness aid” tablet
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CHEM 14 CL
10(A) – CAFFEINE EXTRACTION AND PURIFICATION AND CHARACTERIZATION FROM
“ALERTNESS AID” TABLETS Post-Lab
(A) Abstract
Outline the objective of the experiment as well as any experimental results that obtained. Include any
technique that you used in the lab to isolate, purify and analyze the experimental products.
Caffeine is a naturally occurring compound found in Coffee plants. It is a class of compounds called
alkaloids whose distinguishing feature is a basic nitrogen group contained somewhere in the molecule. In
the purification of caffeine from caffeine tablet, the differing physical and chemical properties are
considered. A large amount of salt is added to increase the polarity of the aqueous layer so that the caffeine
will dissolve better into the ethyl acetate. Anhydrous sodium sulfate was later used to get rid of any
remaining water and soluble acid in the remaining organic layer. We did this couple of times to make sure
no more water stays in our organic layer. Later the organic layer, which contained caffeine and ethyl acetate
was boiled off and crude caffeine was extracted for later UV, spectroscopy TLC analysis. From the
experiment 0.0958g of caffeine was extracted. The percentage of caffeine recovered, based on the weight
of our original caffeine tablet was about 17.65%.
(B) Data, Observations and Data Analysis from the Caffeine Video
(i) Write all observations from video as well as numerical data in an organized manner.
Weight of Empty weight boat = 2.0859g
Weight of caffeine tablet + weight boat = 2.6287g
Weight of caffeine tablet = 0.5428g
Weight of NaCl = 5.8676g
Weight of empty Vial = 4.1396
Weight of vial + caffeine before complete evaporation of Ethyl Acetate= 4.4205g
Weight of vial + caffeine after 1 additional day for complete evaporation of Ethyl Acetate= 4.2354g
Weight of recovered caffeine = 0.0958g
(ii) Explain why is sodium chloride added and explain the phenomena (physical changes) behind each step
of the observation
NaCl was added during extraction to help increase polarity of aqueous layer and decrease solubility of
compound in aqueous layer. Hence, increase amount of caffeine remaining in organic layer.
(iii) Calculate the % caffeine that you recovered from the tablet.
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