twodogs (Stranger)
05-12-03 17:23
No 432869
      Gassing with xylene  Bookmark   

I have had a quick search but could find no direct reference to anyone gassing with xylene. I am assuming that it would be as equally effective as toluene. Is this correct?
 
 
 
 
    hCiLdOdUeDn
(Hive Addict)
05-12-03 17:46
No 432872
      Yes...  Bookmark   

Gassing in xylene works well. It can hold a little bit more more water per liter than toluene, but has about the same properties of toluene like density, except xylene's BP is slightly higher than toluene.
 
 
 
 
    bones
(Stranger)
05-12-03 18:34
No 432877
      yeah... mabey dry it first  Bookmark   

yeah... mabey dry it first
 
 
 
 
    gabd
(Hive Bee)
05-12-03 21:33
No 432906
      Are u sure about that hidencloud  Bookmark   

Are u sure xylene hold more water then toluene?
I think its the opposite

From msds sheets:

For Xylenes

H2O/oil = 0.00075

and for Toluene

H2O/oil  = 0.0026

So toluene can hold 2.6 part water per thousand part toluene
and xylene 0.75 parts per thousand


As for gassing, xylene works great. I never used anything else and never had any problems. Of course always dry your xylene with epsom salts before gassing.
 
 
 
 
    carboxyl
(Hive Addict)
05-13-03 22:37
No 433079
      I have gassed in both xylene and toluene,...  Bookmark   

I have gassed in both xylene and toluene, there were no strikingly noticeable yield differences as both were done on the same scale. If you are gassing, I can't stress how important dryness is. When there is water contamination, there is a mess.

Don't misunderestimate a person if he or her is working toward the embetterment of America.
 
 
 
 
    mindlib
(Hive Bee)
05-14-03 14:50
No 433195
      When solvents are frac-distilled, is it ...  Bookmark   

When solvents are frac-distilled, is it necessary to use drying agents as well..?
Thanks
or UTFSE?
 
 
 
 
    Rhodium
(Chief Bee)
05-14-03 17:03
No 433218
      Need for drying agent even if distilling  Bookmark   

UTFSE. It depends on if the solvents form azeotropes with water. Ethanol for example cannot be fractionately distilled to more than ~95%, to get 99%+ ethanol you need to use drying agents like Mg/I2 or CaO (see TFSE).
 
 
 
 
    Organikum
(Hive Addict)
05-14-03 19:41
No 433240
      absolute waterfree ?  Bookmark   

Why do you not evapourate/softly boil out the water for your  dryness? Adding an alcohol (IPA, EtOH, MeOH..) should form an even easier to distill tertiary azeotrope by which the remaining nonpolar will get as nonaquaeous as can be made by means of distillation.  Boiling points differ more than 20C for water/xylene and even more for the tertiary azeaotrope as far as I remember - no problem.

?
 
 
 
 
    ClearLight
(Hive Addict)
05-15-03 13:05
No 433394
      Dry ice?  Bookmark   

Can dry ice be dropped into a solvent to scavenge/freeze out the H2O?

Infinite Radiant Light - THKRA
 
 
 
 
    Anansi
(Hive Bee)
05-15-03 22:32
No 433481
      drying solvents with dry ice?  Bookmark   

Just a guess, but I would've thought that the more the dry ice cools the solvent to freeze out any water, the more prone the solvent will be to further moisture condensing into it from the atmosphere due to it being chilled...

Correct me if I'm wrong, but intuitively I'd say this won't work well to try the solvent.

...Anansi
 
 
 
 
    catastrophe
(Hive Bee)
05-16-03 10:15
No 433576
      It's a very bad idea  Bookmark   

CO2 will cause formation of carbonate from the freebase, which may precipitate depending on its solubility in the hydrocarbon you choose (toluene or xylene). When you gas, you'll neutralize the carbonate and form more water. Just follow the standard procedure.