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Author: Subject: Hydrophiles and Dessicants
jimmyboy
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[*] posted on 22-11-2006 at 18:22
Hydrophiles and Dessicants


i was wondering what the strongest drying agents would be if you put them in order of strength.. sulfuric acid and calcium chloride come to mind - would sulfuric steal the water from everything else i wonder? didnt really find any kind of "list of hydrophiles" on google or a measure for them

this is for drying organics - maybe lithium or magnesium metal would be the strongest since they covert water to hydrogen - nah then your left with hydroxide/alkali that could react - acids are probably the best way to go


i also saw this video on zero point energy - pretty neat -- too bad its a hoax

http://www.youtube.com/watch?v=MLl3VAbUEGY
http://en.wikipedia.org/wiki/Hutchison_effect


[Edited on 23-11-2006 by jimmyboy]
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leu
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[*] posted on 22-11-2006 at 19:54


It's not nearly as simple as which agent is stronger as this depends on what compound(s) are being dried :P In terms of mode of action, drying agents are either physical or chemical: thus different dessicants are used depending on the particular circumstances involved :D



Chemistry is our Covalent Bond
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jimmyboy
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[*] posted on 22-11-2006 at 22:04


well suppose i could use any agent in a drying tube -- which would have the strongest drying power...

say you have a choice between - sulfuric - sodium hydroxide - calcium oxide - magnesium sulfate - calcium chloride and silica gel - what would the order be - strongest to weakest..

[Edited on 23-11-2006 by jimmyboy]
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[*] posted on 23-11-2006 at 12:22


Well, there used to be a table of dessicants in the CRC handbook but I understand that it has been removed from recent editions.
For the record the list is;
P2O5
Mg(ClO4)2
BaO
KOH (Fused)
CaO
H2SO4
CaSO4
Al2O3
KOH (sticks)
NaOH (fused)
CaBr2
CaCl2
NaOH ( sticks)
Ba(ClO4)2
ZnCl2
CaCl2
CuSO4
(CRC's copyright- all errors in copying are my responsibillity)
Their table also gives the mass of water left in a litre of air after drying as a quantitative measure of the drying power.
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