hasani10 - 30-10-2022 at 04:26
I've recently found a cheap source for some large rbfs and conical flasks, but they don't have ground glass joints. I want to get them as it would
save me some cash compared to getting the same sizes at 24/29.
Is there an adapter you can use to go from non-ground glassware to ground glassware? I'm imagining just like a simple thing you'd put in a bung with a
female adapter to 24/29 but not quite sure what to search to find it online.
Also, would doing this affect how a distillation/ reflux runs much? Compared to using ground glass joints.
Thanks kindly 
Sulaiman - 30-10-2022 at 04:56
Other than ptfe, resin/rubber/plastic compositions have various chemical compatibility issues with common solvents, acids, bases, oxidisers etc. so
choose your materials carefully.
For simple distillation (no reflux) you could use a stopper with a hole and something like
https://laboyglass.com/glass-straight-inlet-adapter-with-24-...
For refluxing or fractional distillation the gas/vapour has to go up while liquid is falling down,
a hole as small as in the adapter above would choke.
I would rather have two ground glass RBFs than five plain neck RBFs - if of similar cost.
PS I have literally dozens of used PYREX flasks with plain necks - part of a job lot - one day they may be useful - one day...
Texium - 30-10-2022 at 07:59
They’re cheap because they’re virtually useless (the RBFs anyway, the conical flasks are good to have)
Dr.Bob - 30-10-2022 at 12:25
Yes, it is hard to make non-jointed glassware work for real distillations or complex reaction (inert, multineck, etc).
But there are many reactions that are simply stiring chemicals in a flask, and those work fine in any vessel, I use vials, test tubes, bottles, and
other vessels to do simple reactions sometimes, when I have lots of parallel reactinos, or want to test multiple conditions or reagents at one time.
So they may be useful, just not for distillations.