Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: deeogee on April 25, 2004, 09:51:13 PM
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I think i erred. when i tried to recrystalize my crustals out of methanol, i dumped the whole thing into boiling methanol and out it into the freezer. is there anyway to save my work. maybe distilling the methanol. HELP
Edit: Edited title for better indexing. Mitch
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Simply boil the methanol off until you start seeing crystals formed. Once you see the crystals form add a little bit more boiling methanol until all the crystals dissolve again. AND LET THE SOLUTION COOL SLOWLY! This does not mean take it from the heating source and dumping it in the freezer. Making good crystals is an art form and takes a bit of baby cuddling. Sit there and allow the temperature to decrease 5 degrees every half hour or something like that to get good crystals. The slower the process of allowing the methanol to cool the better your crystals will be.
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Is it then possible to recrystallize an infinite amount of times to be sure you've got all the compound out?
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Yes it is. I ofteh have to recrystalize the same solution several times to push product out.
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Yeah, you can recrystallize multiple times in order to get more product out of each mother liquor, but there's a law of diminishing returns.
As for saving the product, just evaporate the methanol off. Then you're left with your original product the same as you had it before. Then start over with the recrystallization bit. You can also try the shortcut that Mitch proposed as well.