Writing Homework Help

Extraction of caffeine

Boil water on a heating plate in a beaker with boiling chips. Measure 20ml of boiling water and add to another beaker containing the tea bag. Keep it for 10 minutes and transfer it to a 35 ml testtube repeat this process 3 more times with 5ml boiling water and keeping it for 5 minutes. Now add 1.1501g of sodium carbonate to the tea prepared and cool it down to room temperature Then add 4ml of dichloromethane (DCM) to the tea, the DCM will be seen separately at the bottom, transfer the DCM from the testtube to another test tube by using a pipette. Repeat the process with 4ml of DCM 2 more times. Add some grams of magnesium sulphate (drying agent) to the extracted caffeine (DCM) solution check for snow globe effect absent add more MgSO4 to absorb water residue. Transfer the DCM solution to a dial via microscale filtration, with pipette by twisting a piece of Kim wipe to the tip of the test tube that prevents entry of MgSO4 particles. To extract caffeine, evaporate the DCM from the solution by placing it in sand bath on a hot plate. After evaporating the DCM keep the vial closed for one week. To check the purity of the extracted caffeine setup TLC with extracted caffeine and pure caffeine. Set ethanol as solvent, soak filter paper in the chromatography chamber after covering. Spot two spots on the TLC paper one with pure caffeine and another with extracted caffeine. Now continue with chromatography experiment, cover the chamber. Take the paper after a few minutes check the solvent front, observe under UV light and mark the spots after the experiment, now compare the two spots.

Data

Mass of sodium carbonate: 1.1501g

Mass of the vial: 16.6032g

Mass of tea leave in the tea bag: 2.8981g

Length moved by the extracted caffeine after TLC: 2.4 – 5.4cm

Length moved by pure caffeine after TLC: 2.6 – 5.4cm