You are provided a neutral (pH 7.0) aqueous solution of citric acid, caffeine, and triethyl amine. Provide a flow chart for how you would isolate pure caffeine from this mixture using, calcium carbonate, dichloromethane, sodium sulfate(drying), and any techniques necessary(ex. evaporation, filtering). Be detailed in your flow chart.
citric acid - pKa 3.1, 4.76, 6.4
protonated caffeine - pKa 1.22
protonated triethylamine - pka 10.75
carbonic acid (fully protonated CaCO3) - pka 10.3, 6.4