Db33 - 2-12-2016 at 08:01
ive seen this done on youtube but i was wondering if its wrong. I was wondering if its safe to heat a round bottom flask on top of a flat
hotplate/stirrer instead of a heating mantle?
elementcollector1 - 2-12-2016 at 08:14
You can, but I would recommend a sand bath or oil bath to ensure even heating.
Amos - 2-12-2016 at 09:18
Wrapping aluminium foil around the flask in a conical shape will keep hot air in and much better insulate the flask for faster and more even heating,
as well.
Chlorine - 2-12-2016 at 10:09
You can perform a hot air bath by encompassing the flask in a cone of aluminium foil about 3 cm above the hot plate.
Texium - 2-12-2016 at 12:27
@Db33: You already asked this question and I merged it to the short questions thread and answered it. Next time check there. Please do not double
post.
MrHomeScientist - 2-12-2016 at 13:04
You also don't want the flask to actually touch the hot plate - that creates a small point of high temperature in the glass that causes thermal
stress. For an air bath, securing the flask slightly above the plate and wrapping in a cone of foil as suggested above works pretty good.
Sand baths are also an option, but I damaged my hot plate with one because, as an insulator, sand baths can overheat the hot plate surface. They've
worked fine several times before, but I just got unlucky the last time.