Mabus - 6-5-2018 at 11:27
I bought a flat bottom one a few weeks ago to dry a solution, worked pretty good, though I can't see if there are any advantages over a round bottom
one.
Are there any significant differences between these two?
Sulaiman - 6-5-2018 at 12:03
I do not know whether round or flat is best,
I just want to mention that borosilicate petri dishes with covers are presently quite cheap via eBay,
they can be used as a petri dish, or as two evaporating dishes 
Mabus - 6-5-2018 at 14:01
The only thing I do not like about using Petri dishes as evaporating dishes is that it's really annoying to scoop up the solid from the edges. I used
one a while ago to grow some crystals, and while I liked that I could scrape off the solid from the flat surface easily, getting it out of the edges
was frustrating.
[Edited on 6-5-2018 by Mabus]
Doc B - 6-5-2018 at 16:27
Flat bottom dishes are better than round when being heated upon an electric hotplate. While round dishes are better than flat when being heated by a
bath or open flame.
alking - 13-5-2018 at 08:41
One thing that comes to mind is that it depends what you are evaporating. If you're collecting a liquid then a round one will be better because it
would all be concentrated in the center where as with a flat one it will pool all around the edges and you'll have a lot more mechanical loss. I'd
imagine to a lesser extent flat ones are better for solids/crystals since they are easier to scrape up on a flat surface than a curved one.