I'm drying some acetic acid after distillation using copper sulphate. I'm trying to remove all the sulphate, tried cooling it, but its still blue, is
there any way to remove it.
Cheers
[Edited on 21-3-2014 by andy]
[Edited on 21-3-2014 by andy]numos - 20-3-2014 at 23:13
Distill at 110-130oC and collect acetic acid. CuSO4 is a salt so it will stay behind.
[Edited on 3-21-2014 by numos]andy - 21-3-2014 at 01:49
Cheers numos, but won't the crystal decompose releasing 4 water molecules, would need alot of steps to remove the water?gdflp - 21-3-2014 at 06:19
Yes it would actually, copper sulfate pentahydrate dehydrates at around 110C and acetic acid boils at 118C. After distilling try using anhydrous
magnesium sulfate instead, that dehydrates at around 150C so you should be able to distill the acetic acid no problem.Zyklon-A - 21-3-2014 at 06:37
Not to mention the equilibrium:
CuSO4 + 2 C2H4O2 ↔ Cu(C2H3O2)2 +
H2SO4.
[Edited on 21-3-2014 by Zyklonb]numos - 21-3-2014 at 09:38
Oops my bad... Well I can't see any other way gdflp is right... CuSO4 is not the best drying agent for this purpose. But correct me if I'm wrong but
wouldn't a vacuum distillation solve this problem? It would lower the boiling point enough to not affect the CuSO4.
edit: at 0.57atm the boiling point of acetic acid is 90oC
[Edited on 3-21-2014 by numos]
[Edited on 3-21-2014 by numos]nannah - 18-12-2014 at 08:37
What was your conclusion? Do you think that vacuum distillation was the better way to dry your acetic acid?
Not to mention the equilibrium:
CuSO4 + 2 C2H4O2 ↔ Cu(C2H3O2)2 +
H2SO4.
[Edited on 21-3-2014 by Zyklonb]
H2SO4 is BY FAR the strongest acid of the two, so that equilibrium lies very much to the left, even with glacial acetic acid. Weaker acids cannot
displace stronger ones.
Not to mention that acetic acid is far more volatile than H2SO4, which by Le Chatelier would drive it further to the left, on distillation.
[Edited on 18-12-2014 by blogfast25]unionised - 18-12-2014 at 10:58
Dropping the pressure will also reduce the temperature at which CuSO4.5H2O loses water.
Which one drops more is anyone's guess.
