Difference between revisions of "Tetrachlorocupric acid"
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==Properties== | ==Properties== | ||
| − | + | ===Chemical=== | |
| − | + | ||
When exposed to copper, the tetrachlorocuprate ion comproportionates with the copper metal to form the dichlorocuprate(I) ion: | When exposed to copper, the tetrachlorocuprate ion comproportionates with the copper metal to form the dichlorocuprate(I) ion: | ||
| Line 19: | Line 18: | ||
Tetrachlorocuprates are able to dissolve many other metals, notably aluminum. | Tetrachlorocuprates are able to dissolve many other metals, notably aluminum. | ||
| + | |||
| + | ===Physical=== | ||
| + | Tetrachlorocupric acid exists as a green solution due to the presence of [[tetrachlorocuprate]] ions. It is stable, but may emit some hydrogen chloride, so it should be stored in a capped container to prevent degradation. | ||
==Production== | ==Production== | ||
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Crude tetrachlorocupric acid can be made by mixing 2 moles of a strong acid, 1 mole of a copper salt, and 4 moles of a chloride source, preferably [[sodium chloride]] or [[potassium chloride]]. The [[spectator ions]] should not interfere. Do not use [[nitric acid]] for this, as it will create [[aqua regia]] and decompose. (Nitric acid itself works as a PCB etchant.) | Crude tetrachlorocupric acid can be made by mixing 2 moles of a strong acid, 1 mole of a copper salt, and 4 moles of a chloride source, preferably [[sodium chloride]] or [[potassium chloride]]. The [[spectator ions]] should not interfere. Do not use [[nitric acid]] for this, as it will create [[aqua regia]] and decompose. (Nitric acid itself works as a PCB etchant.) | ||
| + | |||
| + | ==Projects== | ||
| + | *PCB etching | ||
| + | |||
| + | ==Handling== | ||
| + | ===Safety=== | ||
| + | Tetrachlorocupric acid is corrosive and poses some toxicity being a copper compound. | ||
| + | |||
| + | ===Storage=== | ||
| + | In closed bottles. | ||
| + | |||
| + | ===Disposal=== | ||
| + | Can be neutralize with any base. | ||
| + | |||
| + | ==References== | ||
| + | <references/> | ||
| + | ===Relevant Sciencemadness threads=== | ||
[[Category:Chemical compounds]] | [[Category:Chemical compounds]] | ||
Revision as of 19:04, 25 December 2015
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Tetrachlorocupric acid is an acid formed from the tetrachlorocuprate ion. It is not stable as a solid, rather converting back to hydrochloric acid and copper(II) chloride. However, it is an extremely useful printed circuit board (PCB) etchant.
Contents
Properties
Chemical
When exposed to copper, the tetrachlorocuprate ion comproportionates with the copper metal to form the dichlorocuprate(I) ion:
CuCl42- + Cu → 2CuCl2-
For simple etching, the presence of tetrachlorocuprate is enough to do the job. However, the acidity of tetrachlorocupric acid has the added bonus of allowing the solution to regenerate and be reused when exposed to air:
4H+ + 8Cl- + 4CuCl2- + O2 → 4CuCl42- + 2H2O
This reaction can be accelerated by adding hydrogen peroxide.
Tetrachlorocuprates are able to dissolve many other metals, notably aluminum.
Physical
Tetrachlorocupric acid exists as a green solution due to the presence of tetrachlorocuprate ions. It is stable, but may emit some hydrogen chloride, so it should be stored in a capped container to prevent degradation.
Production
Pure tetrachlorocupric acid is not commerically available, but it can be made easily from hydrochloric acid and copper(II) chloride by mixing them together in a 2:1 molar ratio. It can also be made by dissolving copper(II) oxide, copper(II) carbonate, or copper(II) hydroxide in hydrochloric acid in a 4:1 molar ratio.
Crude tetrachlorocupric acid can be made by mixing 2 moles of a strong acid, 1 mole of a copper salt, and 4 moles of a chloride source, preferably sodium chloride or potassium chloride. The spectator ions should not interfere. Do not use nitric acid for this, as it will create aqua regia and decompose. (Nitric acid itself works as a PCB etchant.)
Projects
- PCB etching
Handling
Safety
Tetrachlorocupric acid is corrosive and poses some toxicity being a copper compound.
Storage
In closed bottles.
Disposal
Can be neutralize with any base.
