PlatinumCal99 - 5-8-2007 at 17:56
Lets say that something is being refluxed, but it is only a small quantity and there are no small flasks to use. So I have to use a much larger flask.
Is there a general rule of thumb to use when determining if a flask is too big? Lets say, for example, refluxing 100ml of something in a 250ml flask
vs a 500ml flask. Is the second one a big no-no? I tried something like that about two months ago and some of my product ended up out of solution on
the walls of the flask
Also, how far up the flask should the oil go when something is being heated on an oil bath? About equal with the contents of the flask or what?
I imagine I should have figured these things out earlier before I started messing around, I know
bio2 - 5-8-2007 at 19:38
Somewhere around 10-15% full you will end up with as much substance clinging to the apparatus as you are able to recover.
Pear shaped flasks are good for small amounts and are sometimes called "recovery flasks"
The oil bath should be at least as deep as the flasks contents.
It will work with less but the bath will need to be heated
much hotter to maintain the same reflux rate for example.