freedompyro
holmes1880
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Separation of Copper Sulfate from H2S04
So I have boiled down a solution of H20, H2S04, and CuSO4. I now have pretty much just H2S04 and CuS04 with trace amounts of water.
How would I go about removing the remaining acid and getting pure CuS04? My only thought at the moment is to add ethanol as CuS04 is ethanol insoluble
and H2S04 is... I think. Not sure if that would work.
But, maybe there is a easy way. Maybe just pour off as much H2S04 as possible and add household ammonia and boil it down?
If I add sodium bicarbonate to neutralize I think I would end up with sodium sulfate... Blah, that is back to step 1! Both CuS04 and sodium sulfate
are soluble in water and insoluble in ethanol. Maybe I should have just let the solution evaporate into large crystals(takes a LONG time to
evaporate)... Washed them quick and that would give a pure product.
Any ideas?
Besides just ordering Copper Sulfate from a pottery/ceramics chem supplier...
[Edited on 21-12-2011 by freedompyro]
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Chemistry Alchemist
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If you still have water as well as the acid with the CuSO<sub>4</sub> and you add sodium bicarbonate, you will get sodium sulfate but also
the dissolved copper sulfate in the water will just react with the sodium bicarbonate to get copper carbonate... the best thing to do which i would
suggest is boil down till no more water is present... copper sulfate is insoluble in cont. sulfuric acid im pretty sure (maybe wrong) so once you just
have the acid and the salt, just poor off the acid and then wash it with ethanol to get rid of any acid and then let it dry... you should always like
you said, let it evaporate to get large crystals and then poor off the remaining solution
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hissingnoise
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Yes, anhydrous CuSO<sub>4</sub> should precipitate as colourless crystals in conc.
H<sub>2</sub>SO<sub>4</sub>.
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Bot0nist
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I make all the copper sulfate I use with the H<sub>2</sub>O<sub>2</sub>, H<sub>2</sub>SO<sub>4</sub>,
and copper conductor. I know, I know, its inefficient as hell, but peroxide is cheap and I'm to lazy to build an electrochemical cell for it right
now. Anyways, Chemistry Alchemist is right. Copper sulfate is barely soluble in conc. sulfuric acid. Boil down your solution until the BP raised well
above 100C (Like 120C) then allow it to cool slowly ( I wrap the beaker in dry tissue and put it in a preheated thermos). After 24 hours of slow
cooling HUGE crystals of copper sulfate will form and are easily separated by decanting.
Also, copper sulfate will crash (precipitate all at once) from a solution of water and sulfuric acid if a good quantity of cold and fairly dry ethanol
or IP alcohol is added. Pulverize and dry ate low temps in the oven to get the whitish-gray copper sulfate that is useful as a desiccant.
http://www.sciencemadness.org/talk/viewthread.php?tid=14644&...
http://www.sciencemadness.org/talk/viewthread.php?tid=14644&...
[Edited on 21-12-2011 by Bot0nist]
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.
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freedompyro
holmes1880
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Can someone convert this concentration to percent? I can't figure out what this means... Trying to convert my CuO into Copper Sulfate to get a bunch
faster than electrolysis.
Dilute sulfuric acid, 0.5 mol dm-3, 20 cm3
http://www.practicalchemistry.org/experiments/reacting-coppe...
Trying to solve this... It actually means 0.5moles of H2SO4 per 1000mL. A mole of sulfuric acid is 98g...
So the solution is: 20mL of 5% Sulfuric Acid per 1g CuO!!! That better be right...
Now, if that is correct... It appears I can increase the concentration and use less solution. Water can hold 320g+ of copper sulfate per 1000mL at the
temperatures the reaction is going to be at. Hmmm... So I can't see any problem with dividing that formula by four and multiplying by four.
5mL of 20% Sulfuric Acid per 1g CuO.
Someone please correct me if I'm wrong. Sigh... What do you know? I'm starting to learn chemistry. 
To keep things simple on the acid side... I am just going to convert my 93% H2SO4 solution to a 20% solution by weight.
100g 93% H2SO4 will be added to 372g H20 to get a 20% solution. Got 372 by multiplying 93 by four.
Edit: Wait a minute... Maybe I should be working by volume, not weight... Ack! Getting dizzy...
Quote: Originally posted by Bot0nist  | Boil down your solution until the BP raised well above 100C (Like 120C) then allow it to cool slowly ( I wrap the beaker in dry tissue and put it in a
preheated thermos). After 24 hours of slow cooling HUGE crystals of copper sulfate will form and are easily separated by decanting.
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Ohhh... There we go!!! That's the ticket. Thanks man!
[Edited on 22-12-2011 by freedompyro]
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