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APO
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What are your desiccants?
I simply think it would be fun to share which desiccants we each have. The only extremely hydroscopic substance I have currently worth noting is
Anhydrous Copper Nitrate.
"Damn it George! I told you not to drop me!"
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Lambda-Eyde
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I only really have calcium chloride and brine... I've also used NaOH in some instances. Need to get some more.
Quote: Originally posted by APO  | | The only extremely hydroscopic substance I have currently worth noting is Anhydrous Copper Nitrate. |
Did you make this yourself? If so, how did you make it? Also, *hygroscopic
This just in: 95,5 % of the world population lives outside the USA
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APO
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I bought the Anhydrous Copper Nitrate from some place in Estonia. I'll post when I attempt to make some though.
"Damn it George! I told you not to drop me!"
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confused
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NaOH when i can my hands on it, otherwise an oven, or just waiting for it to evapourate naturally (which can take ages...especially if there is alot
of solvent)
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Pyro
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CaCl2, NaOH, P2O5
all above information is intellectual property of Pyro.  |
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elementcollector1
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NaOH, H2SO4, CaCl2 (although it's reeeeeally slow)
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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chemcam
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My desiccants are CaCl2, NaOH, Activated Alumina, H2SO4, I am in the market for molecular sieves, anyone know a good place to buy or at least get more
info? I have looked but do not like the resources I have found.
I almost forgot, I always salvage the desiccator packages that come in consumer products/food. Most common are silica beads and activated carbon.
I never have this problem, depending on how much solvent there is just change the size of the evaporating dish.
EDIT: Rewording to sound better
[Edited on 5-10-2013 by chemcam]
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woelen
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Some dessicants I have are
P4O10
CaCl2
NaOH
Na2SO4 (anhydrous)
silica gel
molecular sieves (300 pm)
@APO, I do not believe that you have anhydrous Cu(NO3)2. This chemical is very difficult to prepare and even professional labs usually don't have this
chemical in stock, so I would be very surprised if you have the anhydrous compound. Before the 1960's it was thought that anhydrous copper nitrate was
not possible and nowadays it is a lab curiousity.
Commercially available copper nitrate is the tri-hydrate or hexa-hydrate. These hydrated compounds are true salts, the anhydrous compound is a
volatile covalent compound.
@APO: Is your copper nitrate bright blue like the picture below?
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Hexavalent
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I attest - anhydrous copper nitrate, as woelen pointed out, is a volatile, covalent and strongly nitrating compound and very special conditions are
needed to prepare it, as woelen detailed in another thread:
| Quote: Originally posted by woelen |
[It involves] dissolving copper in liquid NO2, in which some N2O5 was dissolved. The NO2 was diluted with some solvent (IIRC it was CH2Cl2) in order
to make the reaction less vigorous. On evaporation of the solvent, the NO2 and N2O5 at reduced pressure, a solvated solid remains, Cu(NO3)2.xNO2 (I
don't remember x anymore, I think it is 2). On careful heating of this solid (at 80 C or so), the NO2 slowly is given off and anhydrous copper (II)
nitrate remains. |
[Edited on 10-5-2013 by Hexavalent]
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APO
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The Anhydrous Copper Nitrate I have is a MUCH deeper blue than that. I thought it would be white like Anhydrous Copper Sulfate. Once it settles in the
bag for a while it becomes hard as a rock!
"Damn it George! I told you not to drop me!"
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chemcam
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| Quote: Originally posted by APO | | The Anhydrous Copper Nitrate I have is a MUCH deeper blue than that. I thought it would be white like Anhydrous Copper Sulfate. Once it settles in the
bag for a while it becomes hard as a rock! |
How do you know it is anhydrous? I have copper nitrate that is very deep blue and it is a hydrate so you can't judge it by color really. I posted a
picture of it in the "drying copper nitrate" thread so I don't want to repost it.
If I had anhydrous copper nitrate I can tell you I certainly would not store it in a bag unless it was vacuum sealed or under inert atmosphere.
Preferably in an ampule since I would add it to my rare chemical compounds collection. If it is exposed to air it is not anhydrous anymore.
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APO
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I'm pretty sure it's under Argon.
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GammaFunction
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I inquired about a group purchase of sieves. Nobody was interested. My problem is that I'm at a place where shipping is expensive unless USPS, but
most companies do UPS.
deltaadsorbents.com has good prices in bulk; $4/lb at 25 lbs. Redistribute by medium flat rate boxes, and you've got a good group buy deal.
Also, the CRL glass-window sieves on Amazon are apparently 3A.
Incidentally, some kinds of kitty litter are silica gel. I've thought of getting it to protect my tools.
[Edited on 11-5-2013 by GammaFunction]
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woelen
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| Quote: Originally posted by APO | | The Anhydrous Copper Nitrate I have is a MUCH deeper blue than that. I thought it would be white like Anhydrous Copper Sulfate. Once it settles in the
bag for a while it becomes hard as a rock! |
Well, then it is not anhydrous. Anhydrous copper nitrate is not
blue, it is fairly dark green with a bluish hinge.
You can easily confirm the presence of water in your material. Take a test tube, put appr. half a gram of solid in it and carefully heat above a
flame. You'll see formation of copious amounts of red fumes and droplets of nitric acid will collect in the cooler places of the test tube. The test
tube will get a frosty appearance.
Another indication of your copper nitrate being hydrous is the mere fact that you could buy it. A 13-year old boy will not have the money to purchase
anhydrous copper nitrate. I do not know exact prices for that, but I think that a few hundreds of grams of that material will cost you a little
fortune.
[Edited on 11-5-13 by woelen]
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Fantasma4500
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apparently many have CaCl2.. i see why.. its of what ive seen better than NaOH, it doesnt decompose on strong heating and its not melting or etching
anything (alike NaOH) also its easy to get a hold of..
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Eddygp
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I use NaOH. I can't have access to anhydrous CaCl2 and for most reactions I do, NaOH is more than enough.
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username |
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Finnnicus
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My pool grade CaCl2 is good, but not preferable.
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Thebrain
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If there's a better dessicant than phosporous pentoxide, I can't even imagine it.
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blogfast25
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Has anhydrous MgSO4 been overlooked here? From Epsom Salt, this is OTC, cheap and cheerful and useful to dry organic liquids with.
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Metacelsus
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Anhydrous MgSO4 is what I use. Just heat up the epsom salt (on a hotplate or in the microwave). It's great for organic workups.
[Edited on 11-5-2013 by Cheddite Cheese]
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APO
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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.
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chemcam
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Ok you can test how by the above mentioned method, but be sure you open the sealed bag in a water free, inert atmosphere like a sealed glove box or
similar.
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APO
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Sorry, skimmed over that. I'll start building an inert atmosphere glove box.
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chemcam
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That is actually a really good idea, it is a fun project and will have many uses, it is also something you can achieve with your skill level. Posts
like that get you respect.
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DubaiAmateurRocketry
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Lithium compounds are extremely hygroscopic as well, more than copper nitrate.
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