arkoma
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Chromium/Nickel Chlorides?
I've been running a flower pot salt bridge cell (per King's Chemistry Survival Guide)to make my own NaOH and using a carbon cathode electrode and a
cheap stainless steel butter knife anode electrode. The anodic liquid is a dark emerald green and i've been chipping off iron oxide from inside the
pot when I service it.
After going here and looking at Woelens wonderful pictures I have come to the conclusion that I have a mixture of Cr/Ni chlorides. I'm a beginner but this
seems to me to be a correct conclusion.
My question is, am I correct? And if so, can I separate the salts?
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thesmug
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Yes, you are correct. Separating the salts might be hard. If you want to separate the ions chemically just electrolyze the mixture (warning:
chlorine). If you want to keep the salts together (as solid Ni/Cr chloride) you could dry the mixture and try to separate them by solubility in other
solvents. I can't think of any other methods at the moment, surely someone else will be able to help more!
[Edited on 5/21/14 by thesmug]
Good eyes
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The Volatile Chemist
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I am completely unfamiliar with this procedure, could someone fill me in? I do know that Chromium and nickel form complexes differently, maybe they
could be used. Woelen would know.
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thesmug
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I know that nickel chloride forms ammine complexes (hexaaminenickel(ii) chloride is one) but I don't believe that chromium does. Let's keep using
hexaamminenickel(ii) chloride. Hexaamminenickel(ii) chloride separates nicely from water on addition of acetone and chromium chloride is insoluble in
acetone so if you add concentrated ammonia and then add a bit of acetone it should layer into water|chromium chloride|hexaamminenickel(ii) chloride.
That diagram might not be right but hexaamminenickel(ii) chloride is a vivid lilac color so it should be easy to differentiate. From here separation
is very easy. I'll try this sometime to see if I'm right.
Good eyes
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The Volatile Chemist
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Quote: Originally posted by thesmug  | | I know that nickel chloride forms ammine complexes (hexaaminenickel(ii) chloride is one) but I don't believe that chromium does. Let's keep using
hexaamminenickel(ii) chloride. Hexaamminenickel(ii) chloride separates nicely from water on addition of acetone and chromium chloride is insoluble in
acetone so if you add concentrated ammonia and then add a bit of acetone it should layer into water|chromium chloride|hexaamminenickel(ii) chloride.
That diagram might not be right but hexaamminenickel(ii) chloride is a vivid lilac color so it should be easy to differentiate. From here separation
is very easy. I'll try this sometime to see if I'm right. |
TheHomeScientist has posted on something similar, what you said makes sense.
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thesmug
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He was the one who suggested I make some hexaaminenickel(ii) chloride a while back so that's why I'm so fond of that chemical in this example. One of
my favorite syntheses ever! It's probably the easiest synthesis ever.
Good eyes
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DraconicAcid
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If you make the solution basic enough, nickel hydroxide will precipitate out, and a complex chromium ion will remain in solution.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Zyklon-A
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Chromium from SS
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arkoma
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| Quote: Originally posted by DraconicAcid | | If you make the solution basic enough, nickel hydroxide will precipitate out, and a complex chromium ion will remain in solution.
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Seems Ni(OH)2 is not only carcinogenic but is pretty damn toxic, too..
Quote from here
| Quote: | Toxicity[edit]
The Ni2+ ion is a known carcinogen in both humans and mice, possibly by entry into cells via phagocytosis [8]. In the CHO cell line, Ni(OH)2, the LC50
dose has been shown to be 3.6 μg/ml. This high level of toxicity relative to other Ni2+ containing compounds is hypothesized to be due to the
insoluble nature of the compound, and concentration in the nucleus.[11] Toxicity and related safety concerns have driven research into increasing the
energy density of Ni(OH)2 electrodes, such as the addition of calcium or cobalt hydroxides.[2] |
Maybe I'll have enough sense to leave this one alone....
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The Volatile Chemist
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| Quote: Originally posted by DraconicAcid | | If you make the solution basic enough, nickel hydroxide will precipitate out, and a complex chromium ion will remain in solution.
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Obviously one of the simplest solutions to the problem.
| Quote: |
Seems Ni(OH)2 is not only carcinogenic but is pretty damn toxic, too..
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Indeed! Be careful.
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thesmug
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I particularly hate nickel compounds because working with them has made me extremely paranoid about getting cancer. Be careful OP!
Good eyes
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