Sciencemadness Discussion Board

Sodium Sulfate extraction

DalisAndy - 20-12-2015 at 22:12

Is it possible to extract or remove sodium sulfate (Na2SO4) from an aqueous solution all also contains a copper compound? I was thinking that a solvent extract after filtering the solution then redisolving it the extracting solvent, possibly an organic solvent. The copper compound has little to no information on solubility or anything for that matter

JJay - 21-12-2015 at 00:46

Sodium sulfate is highly insoluble in ethyl alcohol. I don't know what copper compound you have, but if it is soluble in ethyl alcohol, you can probably chase the sulfate out of solution with alcohol.

Sodium sulfate is very soluble in warm water and much less soluble near freezing temperatures.

unionised - 21-12-2015 at 04:20

Sodium sulphate has rather odd solubility behaviour. It's got a distinct maximum solubility in warm water, but is less soluble below or above that temperature.

Thee's another complication; I'm fairly sure there's a "mixed crystal" compound of sodium sulphate and coper suplhate which might precipitate out and take the copper with it, depending on the circumstances.

What's the copper compound?

DalisAndy - 21-12-2015 at 23:27

Copper metabisulfite. The precursor compound to Chervauls salt. Attempting to make pure cystals of Chervuals salt

diggafromdover - 22-12-2015 at 00:52

Bubble some sulfur dioxide through the solution. You might tease some more Chevreul's salt out.

DalisAndy - 22-12-2015 at 17:31

Don't need to. Once CuS2O5 is isolated I believe I can make very pure crystals of cherveuls salt. Ether though heating or other wise

Amos - 22-12-2015 at 17:52

I was once told that metabisulfite breaks down into bisulfite in solution and isn't reverted back upon crystallizing, but I can't remember the context or say if it's absolutely true.

DalisAndy - 23-12-2015 at 22:25

I suppose you could theorical oxidize it back. BUT there would have to be a small electrical current to oxidize it. If you went the decompose route. At least that's what my drawings show.
(S2O5)-2 -> (SO3)-2 + SO2 + e-1
In theory I could be possible
2 (SO3)-2 + e-1-> (S2O5)-2 + O1/2

DalisAndy - 24-12-2015 at 16:17

after doing some digging. I believe there are two way to go about making CuS2O5. I lack any equipment to do any of these.
1. CuCO3 + 2 SO2 ====> CuS2O5 + CO2
2. 2 {HSO3}-2 <====> {S2O5}-2 + H2O

crystal grower - 26-2-2016 at 03:23

Hello, could you post image of your ch. salt crystals in "chemicals for crystal growing" thread if u sucessfully make them?
Thanks.