Data:
1. Percent yield based on expected extraction for the tea bags (See question sheet)
2. All functional groups labeled on the IR.
3. Expected Melting Point for a pure sample of Caffeine (See questions sheet)
1. What layer is caffeine found in? Why is that? Caffeine can be found in the organic layer. The organic reagent that is being commonly used for caffeine extraction is dichloromethane (DCM). The caffeine will go to the organic layer because caffeine has more solubility in DCM than water.
2. Hypothetically you extracted 78. 3 mg of caffeine from 2 tea bags. Each bag of tea bags contains 56mg of caffeine. What is your percent yield for this reaction? To get the percent yield we used the equation of % yield = (actual yield) / (theoretical yield) x 100 since there's 56 mg of caffeine in each tea bag the theoretical yield is 56 mg x 2 = 112 mg.
% yield = (78. 3) / (112) x 100
% yield = 69. 9 %
3. What are the main peaks that caffeine would show on an IR? Main peaks that will appear in the IR spectra of caffeine:
3000 cm-1 amine stretch
3000 cm-1 sp2 C-H stretch
1700 cm-1 C=O stretch
1600 cm-1 C=C stretch
Conclusion:
1. List any observations for the experiment you noticed, details about caffeine or any other substance.
2. Based on calculated percent yield and data, and the video, was the experiment successful? Was the desired product obtained?
3. What potential sources of error could have occurred? DO NOT write human error! What is the human error, at what points in the experiment could product have been lost and resulted in low yield?
