Was hoping someone could explain what this means to me:
I have a journal article that says to evaporate the solution (I’m making the solution) over sulfuric acid in vacuo at 59 degrees. Any idea what it
means when it says over sulfuric acid?
I sometimes envy people who live in arid climates. Here in the South Texas tropic, even a trace amount of NaOH left out in the open will make a puddle
in just a few minutes. It's really a pain in the a$$. I hadn't heard of sulfuric acid as a desiccant before - learned something new today.
Tomhissingnoise - 30-1-2011 at 13:34
Sulphuric acid is the world's best-known desiccant with NaOH coming in a close second!
vulture - 30-1-2011 at 13:41
Errm, what about P2O5 and Magnesium perchlorate?spirocycle - 30-1-2011 at 20:33
or sodiumhissingnoise - 31-1-2011 at 02:57
Sulphuric acid and sodium hydroxide are just more commonly known as drying agents . . .
I sometimes envy people who live in arid climates. Here in the South Texas tropic, even a trace amount of NaOH left out in the open will make a puddle
in just a few minutes. It's really a pain in the a$$.
I'm sitting in England right now, and mine does it as well. Don't worry about those dessert folk, wait for the cold, cold darkness of night to get
them.
I envy your sunshine.
In terms of drying agents, these are quite possibly the two most useful guides I've ever seen for quick reference. If they're not already on the site,
copies of them should be stored. The link from Erowid is, as usual for the chemistry content of that site, copypasta'd from somewhere else; I have
seen the table elsewhere but can't find it in it's original location with a quick search. That aside, it's the same information but with a dubious
host.
Keep in mind that graduate students at university have managed to have labs evacuated by selecting inappropriate drying agents and curly arrow has a
post up on the first page of his blog at the moment saying "Ooops" after recommending molecular sieves for acetone. It isn't a one agent for all deal,
and even people studying this at university make mistakes when working through all the combinations. It'd be worth printing these babies out and
laminating them.
Well, you learn something new every day. I didn't know that lead and sodium alloy was used as a drying agent (or even that such a material existed as
an article of commerce). Seems to have fallen out of favor, though.ScienceSquirrel - 31-1-2011 at 09:50
Lead - sodium alloy, that takes me back.
Horrid stuff in big glass jars.
It was used to make alkyl leads and their derivatives back in the eighties when people were still researching that stuff.Panache - 31-1-2011 at 14:53
Lead - sodium alloy, that takes me back.
Horrid stuff in big glass jars.
It was used to make alkyl leads and their derivatives back in the eighties when people were still researching that stuff.
you have a reference for the transform
pb+Na--->pbna----->pb4+---->pb(alkyl)4 eg tetraethyllead
ps apologise for the asciScienceSquirrel - 31-1-2011 at 15:47
The lead / sodium alloy was a legacy material that had been used to make lead based organics before I got there.
We had these big jars in the bottom of the fume cupboards despite the fact that we no longer did lead chemistry on a regular basis.
We hung on to them or could not dump them like the stocks of phosgene and thiophosgene.
There are plenty of papers on making tetra ethyl lead.
It is very toxic.
