Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: What are your desiccants?
woelen
Super Administrator
*********




Posts: 8027
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 12-5-2013 at 02:59


I found the anhydrous copper nitrate from this seller.

http://www.ebay.nl/itm/Copper-II-nitrate-anhydrous-reagent-9...

The picture he shows with the petri dish is exactly like the material I have. Mine, however, is sold to me as the tri-hydrate and this color indeed fits the tri-hydrate very well.

The seller may tell that it is anhydrous, but I do not believe that, unless you can really show that it is anhydrous. Heat some of the material in a test tube and see if droplets of nitric acid and/or water are formed.




The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
APO
National Hazard
****




Posts: 627
Registered: 28-12-2012
Location: China Lake
Member Is Offline

Mood: Refluxing

[*] posted on 12-5-2013 at 13:24


Would setting it in open air and tracking how much mass it gains provide usable data?



"Damn it George! I told you not to drop me!"
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 8027
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 14-5-2013 at 03:23


No, that does not tell you anything. It will attract much more water than is present in the tri-hydrate or six-hydrate. It will continue attracting water until it dissolves in it.

[Edited on 14-5-13 by woelen]




The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
MrHomeScientist
International Hazard
*****




Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline

Mood: No Mood

[*] posted on 14-5-2013 at 06:05


In order of frequency, I use KOH, CaCl2, and NaOH. I like KOH because of its strength as a dessicator, and I have more of that than NaOH at the moment. Anhydrous CaCl2 (or possibly the monohydrate) is found in nearly every store around here as Damp Rid moisture absorber, since I am in a humid area. It's not quite as good as the hydroxides, but I have a near limitless supply!
View user's profile Visit user's homepage View All Posts By User
Bot0nist
International Hazard
*****




Posts: 1559
Registered: 15-2-2011
Location: Right behind you.
Member Is Offline

Mood: Streching my cotyledons.

[*] posted on 14-5-2013 at 06:18


KOH
H2SO4
CuSO4 (I like the color change from anhydrous to pentahydrate)
DampRid
MgSO4
These are what I use frequently, some other more special ones are used rarely.




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.
View user's profile View All Posts By User
Endo
Hazard to Others
***




Posts: 124
Registered: 5-1-2006
Location: USA
Member Is Offline

Mood: Cold

[*] posted on 14-5-2013 at 07:24


I have some MgClO4, MgSO4, H2SO4, Anhydrous CuSO4.
View user's profile View All Posts By User
ItalianChemist
Hazard to Others
***




Posts: 172
Registered: 26-1-2011
Location: Italy
Member Is Offline

Mood: No Mood

[*] posted on 15-5-2013 at 07:06


I usually use NaOH as a desiccant. It's very hygroscopic and cheap!
The most hygroscopic compound I've ever seen is vanadyl sulfate.
View user's profile View All Posts By User
ElectroWin
Hazard to Others
***




Posts: 224
Registered: 5-3-2011
Member Is Offline

Mood: No Mood

[*] posted on 2-6-2013 at 10:31


Quote: Originally posted by APO  
According to this "Anhydrous copper nitrate forms deep blue-green crystals and sublimes in a vacuum at 150-200 °C." it fits color specifications. Any way to test if it's truley anhydrous? I got it from eBay seller argon242.


use something that reacts with water?
View user's profile View All Posts By User
APO
National Hazard
****




Posts: 627
Registered: 28-12-2012
Location: China Lake
Member Is Offline

Mood: Refluxing

[*] posted on 4-6-2013 at 04:21


Well, I have lithium, but that may oxidize just from contact with the Copper Nitrate.



"Damn it George! I told you not to drop me!"
View user's profile View All Posts By User
Sulaiman
International Hazard
*****




Posts: 3721
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Online


[*] posted on 25-5-2016 at 03:02


I have used;
Na
P2O5
H2SO4
NaOH
CaCl2
MgSO4
Vacuum
View user's profile View All Posts By User
Eddygp
National Hazard
****




Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline

Mood: Organometallic

[*] posted on 25-5-2016 at 03:35


MgSO4 in organic chemistry is just bliss.




there may be bugs in gfind

[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
View user's profile View All Posts By User
careysub
International Hazard
*****




Posts: 1339
Registered: 4-8-2014
Location: Coastal Sage Scrub Biome
Member Is Offline

Mood: Lowest quantum state

[*] posted on 25-5-2016 at 06:11


Quote: Originally posted by SnehaPatel  
The advent of molecular sieves into the purification and desiccation industry has helped to improve the processes while reducing costs. Molecular sieve 5a, with a pore size of 5 Angstroms, presents a special advantage with its alkali amino silicate structure. Its drying and purification uses stretch from industrial natural gases to industrial liquids. visit for more info http://molecularsievedesiccants.com/


Since you represent a mol sieve supplier, and took the time to post here about your business, do you care to quote terms for a bulk buy for members here? The issue of obtaining reasonably priced mol sieves comes up regularly.
View user's profile View All Posts By User
Trevor9424
Harmless
*




Posts: 26
Registered: 13-5-2016
Location: United States
Member Is Offline

Mood: Corroded

[*] posted on 25-5-2016 at 10:19


I've only used NaOH so far, but I do plan to try to use CuSO4 and MgSO4.

Question:
Can cobalt(II) chloride be used as a desiccant or would it not work or be ineffective? The reason I'm asking is because I don't have a lot of use for cobalt chloride and I want to try to explore more of its uses.
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 5128
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 25-5-2016 at 12:48


Ice.

it's not great- but it's easy to get and it's cheap.
Blowing air over ice then warming it up to room temperature will cause the humidity to drop to about 25% which is fairly dry.
If you need drier air that that, you can still usefully start with ice to strip out the bulk of the water.
View user's profile View All Posts By User
100PercentChemistry
Hazard to Others
***




Posts: 117
Registered: 21-8-2015
Location: On the island of stability
Member Is Offline

Mood: No Mood

[*] posted on 25-5-2016 at 13:40


I use annahydrous CaCl2 or NaOH.
View user's profile View All Posts By User
100PercentChemistry
Hazard to Others
***




Posts: 117
Registered: 21-8-2015
Location: On the island of stability
Member Is Offline

Mood: No Mood

[*] posted on 25-5-2016 at 13:42


I use annahydrous CaCl2 or NaOH.
View user's profile View All Posts By User
JJay
International Hazard
*****




Posts: 3440
Registered: 15-10-2015
Member Is Offline


[*] posted on 25-5-2016 at 16:49


I have a lot of dessicants... the one I use most is calcium chloride.



View user's profile View All Posts By User
XeonTheMGPony
International Hazard
*****




Posts: 1640
Registered: 5-1-2016
Member Is Offline

Mood: No Mood

[*] posted on 25-5-2016 at 17:18


NaOH, H2SO4, CaCl2, Silica gel (Blue indicating), MgSO4 (Anhydrous), Vacuum pump (Mechanical desiccator)

Working on building a vacuum freeze drying system one of these days it'll be finished!
View user's profile View All Posts By User
Eddygp
National Hazard
****




Posts: 858
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline

Mood: Organometallic

[*] posted on 30-5-2016 at 04:15


Not a desiccant per se, but I have a small vial with tetraethylammonium tetrachlorocuprate(II) and it is very deliquescent. So much that just by standing inside a fairly air-tight screw vial, it has started to get slightly more crumbled together, as if it was slightly moist sand.

Btw, 200th post in Chemistry in General.




there may be bugs in gfind

[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
View user's profile View All Posts By User
Panache
International Hazard
*****




Posts: 1290
Registered: 18-10-2007
Member Is Offline

Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein

[*] posted on 13-6-2016 at 03:08
Wow


It's been sometime since I have felt some input of mine may be helpful.

Firstly
For dessicator boxes, of whatever form, simplest is CaCl2, simplest and best is CaO, best overall is p2o5
For solvents mol sieves are completely OTC.
Go to a refrigeration mechanics trade store, in Australia something like a HeatCraft. Go to the drier cores section.
Find the brand on sale that week/month/whatever.
Find the drier core that only does drying(as opposed to drying + acid adsorption etc)
Buy it
At home smash it to pieces with a hammer
Place chunks of it into your acetone/ethanol/etc solvent bottles
An eon ago Rhodium mentioned this technique, it is very sound, refrigeration mol sieves are 3A, small enough pores to not adsorb acetone.
Solid NaOH, great for amines and all carbons (ref Vogel 1956)

Wow I posted again!!




View user's profile View All Posts By User
j_sum1
Administrator
********




Posts: 6333
Registered: 4-10-2014
Location: At home
Member Is Online

Mood: Most of the ducks are in a row

[*] posted on 13-6-2016 at 04:55


Great to see you, Panache.
Your last four posts were nine months apart. Don't leave it so long. :)




View user's profile View All Posts By User
 Pages:  1  2

  Go To Top