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That Dissolve Metals or Organic Material
Acids That Dissolve Metals or Organic
Material
Acids are often used to dissolve metals
or organic material. However, certain material are more difficult to
dissolve. They require more potent and specialized acid solutions like aqua
regia for dissolving gold or platiunum and piranha for
clean organic material from the surface of silcon or gold. Presented
here is also a list of acidic solutions that are used to dissolve
various metals or organic material. The acidic
conditions given in the Table
of Acids That Dissolve Metals are appropriate
for etching thin metal films where the dissolving process must be carried
out in
a controlled
manner.
Aqua Regia nd Piranha Solutions
| Aqua
Regia Solution |
|
|
- 3 parts HCl to 1 part HNO3
- Excellent oxidant
- Can dissolve gold and platinum
- Produces yellow fumes from the
the reaction of HCl and HNO3 to produce nitrosyl
chloride, NOCl, chlorine gas, Cl2, and water,
H2O.
|
| Piranha
Solution |
|
|
- 5 parts H2SO4 to
1 part H2O2
- Excellent oxidant
- Removes most organic residues.
- Safety
Note: Always add peroxide to sulfuric acid, never vice
versa!
- This is a self-heating solution
that may even boil when mixed.
|
| Table of Acids That Dissolve Metals |
| Gold, Au |
Aqua regia solution, HCl / HNO3 (3:1) |
| Platinum, Pt |
Hot aqua regia solution, HCl / HNO3 (3:1) |
| Silver, Ag |
NH4OH / H2O2 (1:1) |
| Palladium, Pd |
Hot aqua regia solution, HCl / HNO3 (3:1) |
| Copper, Cu |
H2O / HNO3 (1:5) |
| Chromium, Cr |
HCl / H2O2 (3:1) |
| Nickel, Ni |
HF / HNO3 (1:1) |
| Lead, Pb |
Acetic acid, HC2H3O2 / H2O
(1:1) or dilute HNO3 |
| Molybdenum, Mo |
Hot concentrated H2SO4 |
| Tin, Sn |
HF / HNO3 (1:1) or HF / HCl (1:1) |
| Titanium, Ti |
HF / HNO3 / H2O (1:1:50) or H2O
/ HF / H2O2 / H2O (1:1:20)
or HF / H2O / ethylene glycol (2:1:22) |
| Iron , Fe |
H2SO4 / H2O (1:1) or HCl /
H2O
(1:1) or HNO3 / H2O (1:1) |
|
