University:
Massachusetts Institute of Technology
Course:
5.03 | Principles of Inorganic Chemistry I
Academic year:

2022
Views:

470

Pages:

2
Author:

amrinderjeet kaur

Flow chart of Acid Base extraction 1) Weigh 3. 00g of Aspirin/caffeine mixture. Caffeine: Aspirin (acetlysalicylic acid) 2) dissolve mixture in about 30mL dichloromethane in Erlenmeyer flask and transfer dissolved solution into a separatory funnel. The stopcock of the funnel should be closed. Add about 5mL of the Erlenmeyer flask, rinse it, and put the rest into funnel to ensure all of the sample has left the flask. 3) Add sodium bicarbonate to separatory funnel, add ground glass stopper, pick up separatory funnel and shake it vigorously for about 30 seconds. Vent funnel frequently to prevent buildup of pressure. Place funnel back on stand and let it rest until water layer and organic layer are clearly separated 4) place a beaker under the separatory funnel and open stopcock to allow bottom organic layer to drain into the flask. Drain up until the upper liquid reaches stopcock. Label flask as organic layer (caffeine) 5) place another beaker labelled water layer (aspirin) and drain the rest of the fluid in separatory funnel. Extracting from Water layer: once aspirin sodium salt is present in top water layer, it has been separated from caffeine, and need to get it back to its neutral form. Add HCl to water layer in baker Aspirin precipitates out of solution because It’s not soluble in water due to acid being added, able to separate it out of aqueous layer now. Extracting from Organic Layer: Add drying agent Na2SO4 into flask with dichloromethane layer. Filter out the sodium sulfate through gravity filtration with flute filter paper, funnel and round bottom flask Evaporate the dichloromethane from the mixture with caffeine using rotary evaporation. use vacuum filtration and Buchner funnel apparatus to collect all of the solid aspirin precipitate Caffeine solid and heat it up to ensure all of the water has evaporated from the precipitate. Aspirin solid