• Members of the previous forum can retrieve their temporary password here, (login and check your PM).

Freeze precip in a glass cake pan vs jar (+ naphtha evap ?)

Migrated topic.


Rising Star
My friend is currently freezing naphtha in a cake pan. he won't be seeing it for another 3 days (went on a trip), but since its his 2nd extraction only, he won't really know how to compare with freezing in jars.

He sees these pros and cons:

More surface for crystals to stick to
Less distance for precipitated crystals to travel to reach surface, therefore less time going through solvent possibly being redissolved some

Less handy to pour, although he put saran wrap plus aluminum over it and will cut a small slice on a corner to pour and filter.

Slightly off topic, is it normal for naphtha to be super slow evaporating? He sat his ~400ml naphtha solution in the pan by a fan for 12 hrs and there was NO decrease in depth as he marked it with a marker. He is aware though that quite a few micrometers could have evapped and with a large surface area that could be a few mLs but still... damn. it is VM+P. He is also aware that when a solvent has solute it is harder for it to evap. But I've read on here some stories which seemed to indicate they had much faster evapping naptha.
my friend did it. was the last time he will too. he used saran-wrap also but still noticed water on inside(with naphtha), which is bad.
scraping crystal off the glass was also harder, they spread out quite alot.

he prefers a small bowl. with a lid.

naphtha never evaped for me either, 3 days in ventilation and no less.
Top Bottom