anacharsis
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Evaporation Over Sulfuric Acid
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?
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not_important
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http://en.wikipedia.org/wiki/Desiccator
http://www.postech.ac.kr/class/chem241/basic.htm
http://glossary.periodni.com/glossary.php?en=desiccator
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m1tanker78
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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$$. I hadn't heard of sulfuric acid as a desiccant before - learned something new today.
Tom
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hissingnoise
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Sulphuric acid is the world's best-known desiccant with NaOH coming in a close second!
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vulture
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Errm, what about P2O5 and Magnesium perchlorate?
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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spirocycle
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or sodium
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hissingnoise
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Sulphuric acid and sodium hydroxide are just more commonly known as drying agents . . .
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peach
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Quote: Originally posted by m1tanker78  | | I sometimes envy people who live in arid climates. Here in the South Texas tropic, even a trace amount of NaOH left out in the open will make a puddle
in just a few minutes. It's really a pain in the a$$. |
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.
Drying agents by type and general application - you can see why daniel (curly arrow) likes molecular sieves so much
Solvents and what to dry them with
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bbartlog
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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.
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ScienceSquirrel
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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.
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Panache
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| Quote: Originally posted by ScienceSquirrel | 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 asci
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ScienceSquirrel
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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.
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