Amos - 25-3-2014 at 18:29
This is my first post here so I apologise in advance if I came to the wrong place to post this topic. I plan to synthesize copper(II) sulfate via the
addition of an excess of copper to a mixture of distilled nitric acid and excess concentrated sulfuric acid, following this cycle:
Cu(s) + 4HNO3(aq) = Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)
Cu(NO3)2(aq) + H2SO4(aq) = CuSO4(aq) + 2 HNO3(aq)
I understand this may not be the most cost-effective method, but I was curious about an efficient way to recycle the nitrogen dioxide in the first
step to make more nitric acid. I've tried bubbling it directly into icewater and into hydrogen peroxide but most is still lost in the process. I came
up with the idea of combining nitrogen dioxide and water vapour together in a downward pointing condenser to form nitric acid that will drip out. Can
anyone recall trying something similar or give me advice as to how this will go?
[Edited on 26-3-2014 by No Tears Only Dreams Now]
TheChemiKid - 26-3-2014 at 03:54
The Nitrogen Dioxide would react with water to form Nitric and Nitrous Acids, the Nitrous Acid will either decompose into water, Nitrogen Dioxide, and
Nitrogen Monoxide; or get oxidized by the atmosphere to Nitric Acid.
Just a Warning: Adding Copper to Nitric Acid is a vigorous reaction, bubbling is likely to occur, so use a large reaction vessel.
2NO2 + H2O => HNO3 + HNO2
then,
2HNO2 => H2O + NO2 + NO
or
2HNO2 + O2 => 2HNO3
I have not heard of your exact plan of making the Nitric Acid.
Finally: I understand you know this is not economical, but if your aim in the end is to be economical, just buy copper sulfate from a hardware store,
or if you are set on making it, check out Nurdrage's videos.
Amos - 26-3-2014 at 06:43
Funnily enough, Nurdrage sent me here in the first place. I appreciate the warnings; I've carried this reaction out before and it definitely has a
kick if your copper has a lot of surface area. Thanks a lot for the reactions you posted, now I think I might substitute my water for boiling hydrogen
peroxide in order to introduce some additional oxygen, I think that would increase my yield. I'll post my findings when this is done, though it may
not be for another week.
TheChemiKid - 26-3-2014 at 07:25
Adding Hydrogen Peroxide would increase the yield. Some may decompose, though.
Here is how the reaction would go:
H2O2 + 2NO2 => 2HNO3