Arbetarn - 30-3-2016 at 04:28
Hi i tried to make some Copper Chloride by bubbling air through 99,9% HCl with some copper metal in it, and i found out that my air pump wasnt
sufficient for it so now i just have HCl with copper metal in it. The HCl has gotten a little green tint also, is this the Copper Oxide or something?
What will happen now? And am i able to still make CuCl from it?
crystal grower - 30-3-2016 at 04:38
99,9%HCl? .Did you mean concentrated 36%solution? I dont think that the green tint is copper oxide as it would react with hcl. I would recommend
you using CuO instead of Cu.
[Edited on 30-3-2016 by crystal grower]
j_sum1 - 30-3-2016 at 04:41
The green is copper chloride. Or more specifically the tetrachloro copper complex CuCl42— that forms at high chloride
concentrations.
It is never going to be a fast reaction -- Cu just does not react well with HCl. Bubbling air in will help volatise the HCl and so might not be the
best method. You could try peroxide to assist the oxidation. But I don't know how well that would work.
A more conventional route would be to react copper with nitric acid to produce copper nitrate solution. Then neutralise with sodium carbonate (slowly
since large amounts of CO2 will be produced.) Keep adding sodium carbonate and stirring until a pale green precipitate of basic copper carbonate is
formed. (Cu2(OH)2CO3) This can be filtered and washed. If your reaction is complete the filtrate should be clear.
After that you can react the basic copper carbonate with HCl to get the chloride. Evaporate, crystallise and you are done.
[edit]
By the way, this kind of question belongs in Beginnings. That is the forum for chemistry-related material and questions without references. I'll
page a mod to move it for you.
[Edited on 30-3-2016 by j_sum1]
[edit 2]
Fixed brain-fart typo.
Thanks woelen.
[Edited on 30-3-2016 by j_sum1]
woelen - 30-3-2016 at 06:00
Hydrochloric acid is a solution of the gas HCl in water. Under normal pressure and at normal room temperature, the maximum attainable concentration of
HCl in water is appr. 37% by weight. Such a solution is called "concentrated hydrochloric acid". Higher concentrations are possible, but these require
storage under high pressure and/or low temperature. Commercially, hydrochloric acid is offered in many different concentrations. Where I live, common
concetrations are 10%, 30% and 37% by weight. The last one is a heavily fuming liquid, but the 30% solution also fumes somewhat.
--------------------------------------------------------
Copper metal does not dissolve in hydrochloric acid. Copper oxide does. In the presence of oxygen gas, copper metal can dissolve in hydrochloric acid,
but it does no very very slowly and this reaction has no practical importance.
If you want to make copper chloride, then mix some concentrated hydrochloric acid with a solution of hydrogen peroxide in water and then add the
copper metal to that mix. That mix quickly dissolves copper metal. The product, however, can be very complicated. If excess hydrogen peroxide is used
relative to the amount of copper, then you get the brown/yellow complex CuCl4(2-) (@j_sum1: not CuCl4(2+)) which gives a brown/yellow solution in
conc. hydrochloric acid. In less concentrated hydrochloric acid, such solutions tend to be green, due to formation of free copper ions and partially
chlorinated complexes, such as CuCl2(H2O)2. The more dilute, the more blue the solution becomes.
If excess copper is used, relative to the hydrogen peroxide, then the copper(II) in turn oxidizes copper metal to form copper(I) complexes. E.g.
CuCl4(2-) reacts with copper to form CuCl2(-) ions, which are colorless. These CuCl2(-) ions in turn can react with excess CuCl4(2-) and give very
dark brown mixed-oxidation-state complexes.
Have a look at this page from my website. I have done a lot of experimenting with copper in hydrochloric acid: http://woelen.homescience.net/science/chem/riddles/copperI+c...
macckone - 30-3-2016 at 10:28
Electricity will accelerate the dissolution of copper.
This is used to etch circuit boards but copper will
also be deposited on the other electrode so you
may not get exactly what you want. This is also
used for plating through holes but the hydrogen
chloride concentration in the through hole plating
should be as low as practical. Converting copper
to the oxide is easier with a large surface area.
DraconicAcid - 30-3-2016 at 10:34
I'd just let it sit exposed to air for a while. As the copper starts to react, the products catalyze the reaction.
JJay - 30-3-2016 at 10:43
Adding hydrogen peroxide will greatly speed the formation of copper chloride.
pesco - 30-3-2016 at 12:27
Best method I found while using Copper chloride to etch PCB's.
1)
To start the process:
Cu + HCl + H2O2 -> CuCl2 + 2 H2O
Its pretty fast reaction.
2)
Once you got some CuCl2 in a solution it will etch more copper without H2O2 as per reaction:
Cu + CuCl2 -> 2 CuCl
3)
CuCl is easily regenerated by atmospheric Oxygen providing there is free HCl in a solution
4 CuCl + 4 HCl + O2 -> 4 CuCl2 + 2 H2O
Aerating solution helps a lot, but oxidation will take place without it albeit slowly.
Once its regenerated you are back to point 2)
Usually points 2) and 3) happen simultaneously.
Just drop some copper in solution and aerate it with aquarium pump. Every now and then drop some HCl.
Regards