posted by Anonymous .
Extraction of caffeine:
You had extracted 2 g of crude caffeine and you were in a hurry. Instead of doing the 6 successive extractions with 2ml portions of methylene chloride, you only did 2 successive extractions with 6 ml portions of solvent. Now, calculate the total mass of pure caffeine recovered in these 2 operations.
You didn't provide any data.
K = (organic phase)/(aqueous phase), solve to see how much stays in the aqueous phase, then do the extraction again. I think you will find that 2 extractions of 6 mL each will not be as efficient as 6, 2-mL extractions.