mintreina
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Making cobalt(II) chloride from cobalt(II) sulfate
Is it possible to make CoCl2 from CoSO4 by adding NaCl, in the same way that CuCl2 is made from CuSO4 and NaCl?
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Nicodem
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Thread Moved
22-12-2015 at 01:15 |
Nicodem
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Please provide the reference for "CuCl2 is made from CuSO4 and NaCl".
Open beginners topics only in the Beginnings forum section. Read the forum guidelines for more information.
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j_sum1
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Welcome to SM mintreina.
This place is a mine of information with a lot of highly competent and knowledgeable people. I don't count myself as one of them, but I can answer
your question.
Your best bet for making CoCl2 starting with CoSO4 is to mix up a solution of CoSO4 and add a solution of CaCl2. A precipitate of CaSO4 will settle
out. Filter that and your filtrate will contain CoCl2.
It will be impure -- having a small amount of CaSO4 as well as whichever reactant was in excess. For this reason you should have your reagents as
close as possible to their stoichiometric ratios. You can extract your product through evaporation and crystallisation. Careful recrystallisation
will purify it also.
The reason that NaCl does not work for this is that NaSO4 is soluble. All you will get is a mixture of your ions in solution. OTOH, CaSO4 is
reasonably insoluble and so will form a solid precipitate if both Ca(2+) ions and SO4(2-) ions are present.
Can I recommend, if you plan on hanging around, that you read the forum rules. This site is different from many in that we prefer an old relevant
thread to be resurrected rather than begin a new one. It keeps all the information in one place. There is also a "short questions" thread for
questions like this one.
[Edited on 22-12-2015 by j_sum1]
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mintreina
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Thanks a lot. And sorry for my mistake. I havent read the rules... yet...
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unionised
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Another route (which doesn't involve trying to precipitate CaSO4 which often gives a slime that's hard to filter) is too add a solution of sodium
carbonate to a solution of cobalt sulphate to precipitate cobalt carbonate which you can filter off, wash with water and then dissolve in hydrochloric
aid.
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JJay
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CaSO4 will likely need to be vacuum filtered using a water aspirator or an electric pump. You can gravity filter it, but you will lose a lot of
product.
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blogfast25
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Yes. But you also precipitate the Co<sup>2+</sup> as CoCO3, filter and wash.
Then dissolve the CoCO3 in the correct amount of HCl and if you play it right, 80 % of the CoCl2 will crystallise out as the
hexahydrate.
I did this recently and it worked extremely well.
[Edited on 22-12-2015 by blogfast25]
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elementcollector1
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Quote: Originally posted by JJay  | | CaSO4 will likely need to be vacuum filtered using a water aspirator or an electric pump. You can gravity filter it, but you will lose a lot of
product. |
In my experience, it's possible to do it without either of these. Depends on what concentrations of reagents you use, as that affects the particulate
size.
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blogfast25
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| Quote: Originally posted by elementcollector1 |
In my experience, it's possible to do it without either of these. Depends on what concentrations of reagents you use, as that affects the particulate
size. |
Agreed. And just letting the slurry stand overnight can help filtrability due to increased grain size (crystallisation).
[Edited on 22-12-2015 by blogfast25]
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