antibody
Harmless
Posts: 38
Registered: 4-2-2011
Member Is Offline
Mood: No Mood
|
|
Inert atmosphere, which is best?
Hi
Ab2 is hoping some of the local hazards might be able to weigh in on this subject. Ab2 needs an inert atmosphere for some alkylation work using STAB
and ZnBH4, but at the same time would like use the inert atmosphere to blanket bottles of THF and ethers etc. that have been opened.
Ab2 understands Argon is denser and less reactive than nitrogen, and perhaps more expensive too.
Is argon or nitrogen is the best way to go? Is there an overwhelming reason why one would be preferred over the other? Any words from the wise would
be appreciated.
Also wondering what would be the best regulator for the job. One that would allow a very slow steady trickle of gas. Any suggestions. One supplier Ab2
spoke with suggested a regulator with a needle valve.
Thanks
[Edited on 10-5-2011 by antibody]
[Edited on 10-5-2011 by antibody]
|
|
|
watson.fawkes
International Hazard
Posts: 2793
Registered: 16-8-2008
Member Is Offline
Mood: No Mood
|
|
Who is "Ab2"?
|
|
|
hissingnoise
International Hazard
Posts: 3940
Registered: 26-12-2002
Member Is Offline
Mood: Pulverulescent!
|
|
He's the second person to refer to himself in the third person in a week . . . l☺l
|
|
|
symboom
International Hazard
Posts: 1143
Registered: 11-11-2010
Location: Wrongplanet
Member Is Offline
Mood: Doing science while it is still legal since 2010
|
|
nitrogen or argon is fine for that purpose anything but oxygen because nitrogen does not react with those.
if you make sodium argon is better because nitrogen reacts with sodium to form sodium nitride.
as for regulators a welding supply place would help you there
small nitrogen tanks are used in paint ball
argon in arc welding
now that i think of it co2 tank should work for your purposes too.
co2 is heavier than air. dry ice is a source there.
[Edited on 10-5-2011 by symboom]
|
|
|
antibody
Harmless
Posts: 38
Registered: 4-2-2011
Member Is Offline
Mood: No Mood
|
|
Thanks Symboom!
Actually, Ab2 has been referring to herself in third person for years, its preferable to SWIMing or
FOAFing 
|
|
|
hissingnoise
International Hazard
Posts: 3940
Registered: 26-12-2002
Member Is Offline
Mood: Pulverulescent!
|
|
Wimin make the best cooks! 
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
A thread you may find useful:
http://www.sciencemadness.org/talk/viewthread.php?tid=10366
What's FOAFing?
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
antibody
Harmless
Posts: 38
Registered: 4-2-2011
Member Is Offline
Mood: No Mood
|
|
Thank you magpie
that thread has lots of useful information, not the least of which being that nitrogen has the same density as air, Ab2 was under the misapprehension
that it was heavier than air, very good to know.
|
|
|
a_bab
Hazard to Others
Posts: 458
Registered: 15-9-2002
Member Is Offline
Mood: Angry !!!!!111111...2?!
|
|
To Ab2 it could be a shock that the air contains mostly nitrogen, otherwise I can't explain such a "good to know" fact that N2 is not heavier then
air.
|
|
|
Bot0nist
International Hazard
Posts: 1559
Registered: 15-2-2011
Location: Right behind you.
Member Is Offline
Mood: Streching my cotyledons.
|
|
FOAF = Friend of a friend. Another useless acronym like SWIM meant to help anonymity and plausible deniability in the event that there posts are
scrutinized by LE. I highly doubt its efficacy though.
[Edited on 10-5-2011 by Bot0nist]
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
|
|
|
antibody
Harmless
Posts: 38
Registered: 4-2-2011
Member Is Offline
Mood: No Mood
|
|
It is a surprise a_bab. 
to be honest, Ab2 hasn't spent much time considering the make up of air, but if nitrogen has the same density as air then how would one lay down a
blanket of the gas in a bottle? wouldn't it just float away?
|
|
|
Bot0nist
International Hazard
Posts: 1559
Registered: 15-2-2011
Location: Right behind you.
Member Is Offline
Mood: Streching my cotyledons.
|
|
Quote: Originally posted by antibody  | It is a surprise a_bab.
to be honest, Ab2 hasn't spent much time considering the make up of air, but if nitrogen has the same density as air then how would one lay down a
blanket of the gas in a bottle? wouldn't it just float away? |
If it was less dense it would. A gas of neutral buoyancy should work it the environment is still and of equal temperature.
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
|
|
|
UKnowNotWatUDo
Hazard to Self
Posts: 96
Registered: 30-6-2010
Member Is Offline
Mood: No Mood
|
|
Technically speaking pure nitrogen gas would have a density slightly lower than that of normal air, as the atmosphere is composed of roughly 4 parts
nitrogen and 1 part oxygen. Though I doubt this would make hardly any difference.
|
|
|
turd
National Hazard
Posts: 800
Registered: 5-3-2006
Member Is Offline
Mood: No Mood
|
|
Is ab2 certain that an inert atmosphere is needed at all? I don't think STAB is terribly reactive towards moisture, some reports claim HCHO(aq.).
Combine with moderate temperature and short reaction time, I think it's worth to risk it.
If you have the choice go for argon - cheap enough, good availability and heavier than air.
PS: divine moments of truth, right?
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
