Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: UAphenix on October 03, 2005, 03:25:42 AM
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Can anyone explain to me why sublimation would be used to purify crude caffeine as opposed to recrystallization? I reallize that caffeine doesn't boil, it does sublime though. I may completely wrong here, if you can't tell i am to say the least completely lost. Any ideas would be very helpful. Thanks
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Its a better way to remove impurities.
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Thanks, what makes sublimation a better purifier than recrystallization? I have been looking all over the web to find a comparison of the two, but have not had any luck.
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crystalisation relies on the partial precipitation of a salt based on the difference in solubility at different temperatures.
with sublimation however, u can be assured that all the substance will sublime, just like how water boils completely beyond 100oC