Sciencemadness Discussion Board

Copper (ii) sulfate from CuO and S

ThatChemist89 - 19-8-2024 at 13:59

Hello!
Ive come across a video that states that CuO and S react to form copper sulfide. Which can be turned to copper sulfate which is correct! but i would like some clarification

Procedure used:
A equal amount of CuO and Elemental sulfur were added to a test tube.
A candle was placed under the test tube
After about 2 minuets water was added the solution slowly transitioned to a blue color
The solution was filtered and boiled revealing crystals of Copper(ii)sulfate

now i dont go against the reaction but is the flame of a candle hot enough to do such a reaction? because i would like to obtain copper sulfate to synthesis H2SO4
And i cannot buy it ive tried to bobble sulfur dioxide in H2O2 but lacking a air pump has slowed the process down a lot (a RBF has water and a aluminum boat the sulfur is burned and the RBF is covered the process is done over and over with a lot of sulfur lose!)

Video: https://www.youtube.com/watch?v=vjGg1ad4z2c&t=115s


knowledgevschaos - 20-8-2024 at 05:50

I think that the red powder must be copper (I) oxide, so maybe it is possible that it was reducing the copper.
I still think that there must be a much more efficient way to turn copper oxide into sulfate.

RU_KLO - 20-8-2024 at 12:26

if your end product is H2SO4, there is a lot of information in this forum.

try the wiki (our wiki) first, there are several methods you could try.

You could also try other sulfate, instead of Copper (for example Magnesium Sulfate)
but you need a ion-exchange diaphragm or a "flower pot". Search youtube for scrap science.

if you want to go to the copper - > sulfate route.
(I dont know if it will work but you could try)

1) make copper chloride with copper and HCl.
2) make copper carbonate with copper chloride + sodium carbonate (or sodium bicarbonate
3) make copper sulfate with copper carbonate + any soluble metal sulfate (magnesium, manganese, iron, etc).

As Copper carbonate is almost insoluble, the solution should be heated and refluxed (or loss water by boiling, added). time should be tested, but 1 hour is ok.

The new metal carbonate will precipitate and copper sulfate will stay in solution (lets hope).

Try to have more Copper carbonate as an excess.

(of course if you have H2SO4 you could easily make copper sulfate from carbonate + acid - but the idea is to proceed without H2SO4)

the metal sulfate used, should be "before" in the reactivity series:

Metals: Cs, Rb, K, Na, Li, Ba, Sr, Ca, Mg, Al, Cr, Mn, Zn, Fe,
Cd, Tl, Co, Ni, Sn, Pb, H, Sb, Bi, As, Cu, Hg, Ag, Pd, Pt,
Au, Ir, Rh, Os.

as example (not for this procedure, but to understand the series):

The metal zinc (Zn) displaces copper (Cu) from Copper sulphate because zinc is more reactive than copper. In contrast, copper is not able to displace zinc from Zinc sulphate because it is less reactive than zinc


if you want to go with the sulfide route, take this into account:

Copper sulfides are known to readily oxidize to the sulfate (CuSO4) and oxy-sulfate (CuO·CuSO4) at low temperatures, but these undergo thermal dissociation when the temperature increases, giving the most stable oxide phases (Cu2O and CuO)

"During heating from 298–613 K, adsorbed water was
removed from the concentrate. Present sulphides started
oxidizing at temperatures below 613 K but to a lesser
extent [24]"

613K is 340C which is in the candle flame "cooking" range .(I use simple alcohol lamp and got to 450-500C in small porcelain crucibles)

maybe you could get more info here:
doi:10.1007/s10973-014-3838-8










Attachment: copper sulfide.pdf (1.4MB)
This file has been downloaded 72 times

knowledgevschaos - 20-8-2024 at 21:38

So you're saying (with magnesium sulfate as an example):
MgSO4 Aq + CuCO3 S -> CuSO4 Aq + MgCO3 S ?
My instinct is that this won't work, because the magnesium carbonate could form an unreactive layer over the copper carbonate. The reaction would probably go backwards as fast as it goes forwards.

Maybe you could add a different salt to the copper chloride and then freeze it to try and crystalize out copper sulfate, similar to how you can form potassium chlorate from sodium chlorate and potassium chloride. I don't know what salt you'd use though.

What are you using the copper sulfate for?

RU_KLO - 21-8-2024 at 06:57

Quote: Originally posted by knowledgevschaos  
So you're saying (with magnesium sulfate as an example):
MgSO4 (Aq) + CuCO3 (S) -> CuSO4 (Aq) + MgCO3 (S) ?
My instinct is that this won't work, because the magnesium carbonate could form an unreactive layer over the copper carbonate. The reaction would probably go backwards as fast as it goes forwards.


probably you are right, because:
The Ksp of magnesium carbonate, MgCO3, is 6.82 x 10-6. (from homework.study.com)
The Ksp of copper(II) carbonate, CuCO3, is 1.4×10−10 (from wyzant.com)

so probably as magnesium carbonate is more soluble, it will not work.
So in order to displace copper from the carbonate, we need a metal sulfate which carbonate has a lower KSP than copper carbonate.

Carbonates KSP

CoCO3 8.0 x 10-13

CuCO3 2.5 x 10-10

FeCO3 3.5 x 10-11

Ag2CO3 8.1 x 10-12

ZnCO3 1.5 x 10-11

(https://owl.oit.umass.edu/departments/Chemistry/appendix/ksp...)

it seems that FeSO4, CoSO4, ZnSO4 could work.