why do HCl lose it's corosive influence even for abit, when we prepare a solution with Copper(II) sulfate ?
H2O + CuSO4 + HCl
because of the interaction of the acid and the copper?
# 100 ml HCl %37 + 50 gram Copper(II) sulfate # in 1000 ml solution ... is less corosive than the solution of ;
# 50 ml HCl %37 + 10 gram Copper(II) sulfate # in 1000 ml solution
less corosion, in spite of the existence of more acid with more CuSO4
HCl + CuSO4
Moderators: Xen, expert, ChenBeier
Not because of the interaction of the acid and the copper but rather because of the interaction of iron and copper salt:
Fe + CuSO4 = Cu + FeSO4
Copper creates a coat on the surface of iron or it's alloys and prevents it from corrosion by HCl.
Fe + CuSO4 = Cu + FeSO4
Copper creates a coat on the surface of iron or it's alloys and prevents it from corrosion by HCl.
Remember safety first! Check MSDS and consult with professionals before performing risky experiments.
thank you
thank you very much expert;
I think, this is (Fe + CuSO4 = Cu + FeSO4)
what we want to have, to watch aluminum follio mistakes.
CuSO4 have an interaction with free iron alloys, then have a color nearly orange. Then we wash the surface and watch the holes, called pinhole.
(biggest holes are smaller than 1 mm)
on this step, we need acid to have some free iron alloys from aluminum follio, to create an interaction with CuSO4 and Fe.
do you think so?
I could send some photos of these, if I knew your email.
I 'm not educated chemistry. I studied about food and we need to do this analysis for the packing of our products.
I think, this is (Fe + CuSO4 = Cu + FeSO4)
what we want to have, to watch aluminum follio mistakes.
CuSO4 have an interaction with free iron alloys, then have a color nearly orange. Then we wash the surface and watch the holes, called pinhole.
(biggest holes are smaller than 1 mm)
on this step, we need acid to have some free iron alloys from aluminum follio, to create an interaction with CuSO4 and Fe.
do you think so?
I could send some photos of these, if I knew your email.
I 'm not educated chemistry. I studied about food and we need to do this analysis for the packing of our products.
I realized that this reaction has nothing to do with iron since you have only aluminum foil, and occasionally it has pinholes. The surface around pinholes is rougher and therefore it reacts with copper sulfate first precipitating visible red copper:
Al + CuSO4 = Al2(SO4)3 + Cu
In a case when you use higher concentration of CuSO4, the reduction of Cu(2+) may not proceeding to copper metal as you expect but rather ends up in only partial reduction to Cu(1+)
Al + CuSO4 = Cu2SO4 + Al2(SO4)3
Even if copper precipitates at the first moment, it can react with an excess of CuSO4 and dissolve:
Cu + CuSO4 = Cu2SO4
While Cu metal is completely insoluble and visible, Cu2SO4 is still partially soluble in water, especially in the presence of HCl and therefore you don’t see the result of corrosion. I’m sure the corrosion is stronger in 5% CuSO4. You just don’t see the result of it right away in the latter case.
Al + CuSO4 = Al2(SO4)3 + Cu
In a case when you use higher concentration of CuSO4, the reduction of Cu(2+) may not proceeding to copper metal as you expect but rather ends up in only partial reduction to Cu(1+)
Al + CuSO4 = Cu2SO4 + Al2(SO4)3
Even if copper precipitates at the first moment, it can react with an excess of CuSO4 and dissolve:
Cu + CuSO4 = Cu2SO4
While Cu metal is completely insoluble and visible, Cu2SO4 is still partially soluble in water, especially in the presence of HCl and therefore you don’t see the result of corrosion. I’m sure the corrosion is stronger in 5% CuSO4. You just don’t see the result of it right away in the latter case.
Remember safety first! Check MSDS and consult with professionals before performing risky experiments.
can we create the best recipe ?
OK;
both CuSO4 and HCl is necessary in the solution for the most reliable result. but how can we guess the right concentration of the perfect solution?
Do more CuSO4 or HCl cause defect ?
and more CuSO4 means more cost, about money. if we don't need to use much more, we don't need to spend much more.
we have two different analysis descriptions with two different concentrations.
you know;
1- %5 CuSO4 with %10 HCl
2- %1 CuSO4 with %5 HCl
which one will give the better result ?
or can we create a better recipe?
please tell me some conjecturel recipes, I will try them, then I will observe their results.
thank you.
both CuSO4 and HCl is necessary in the solution for the most reliable result. but how can we guess the right concentration of the perfect solution?
Do more CuSO4 or HCl cause defect ?
and more CuSO4 means more cost, about money. if we don't need to use much more, we don't need to spend much more.
we have two different analysis descriptions with two different concentrations.
you know;
1- %5 CuSO4 with %10 HCl
2- %1 CuSO4 with %5 HCl
which one will give the better result ?
or can we create a better recipe?
please tell me some conjecturel recipes, I will try them, then I will observe their results.
thank you.
Let me summarize here.
At higher concentration of CuSO4, Cu(2+) may reduce not to copper metal (orange) but to Cu2SO4, a "semireduced" copper sulfate that is soluble in HCl in a such diluted solution.
Both copper and acid can react with aluminum but you have to know one very important thing about aluminum. It is a very special metal. It is very chemically reactive and would burn on air or violently react with water if not a tight aluminum oxide layer that quickly forms on the surface of aluminum upon simple exposure to air.
“Chemically, the film is a hydrated form of aluminum oxide. The corrosion resistance of aluminum depends upon this protective oxide film. which is stable in aqueous media when the pH is between about 4.0 and 8.5. The oxide film is naturally self-renewing and accidental abrasion or other mechanical damage of the surface film is rapidly repaired. The conditions that promote corrosion of aluminum and its alloys, therefore, must be those that continuously abrade the film mechanically or promote conditions that locally degrade the protective oxide film and minimize the availability of oxygen to rebuild it.”
http://www.corrosion-doctors.org/MatSel ... alumin.htm
HCl solution may react very slow with aluminum because of this protecting layer. Copper sulfate may not react at all for the very same reason but combination of copper salt and HCl create conditions when copper precipitates on the surface of aluminum and prevents formation of a dense Al2O3 therefore creating conditions for even faster reaction of copper-coated aluminum layer with copper salt. This in fact creates amplification conditions when tiny defects create reaction centers where precipitation of copper prevents formation of protecting Al2O3 layer and it further accelerates reaction with copper (2+) salt. Basically this amounts to amplification where tiny defects of the surface can be pinpointed.
The best conditions for such quality control method should be found experimentally. I would try not only increase but decrease in CuSO4 concentration as well.
At higher concentration of CuSO4, Cu(2+) may reduce not to copper metal (orange) but to Cu2SO4, a "semireduced" copper sulfate that is soluble in HCl in a such diluted solution.
Both copper and acid can react with aluminum but you have to know one very important thing about aluminum. It is a very special metal. It is very chemically reactive and would burn on air or violently react with water if not a tight aluminum oxide layer that quickly forms on the surface of aluminum upon simple exposure to air.
“Chemically, the film is a hydrated form of aluminum oxide. The corrosion resistance of aluminum depends upon this protective oxide film. which is stable in aqueous media when the pH is between about 4.0 and 8.5. The oxide film is naturally self-renewing and accidental abrasion or other mechanical damage of the surface film is rapidly repaired. The conditions that promote corrosion of aluminum and its alloys, therefore, must be those that continuously abrade the film mechanically or promote conditions that locally degrade the protective oxide film and minimize the availability of oxygen to rebuild it.”
http://www.corrosion-doctors.org/MatSel ... alumin.htm
HCl solution may react very slow with aluminum because of this protecting layer. Copper sulfate may not react at all for the very same reason but combination of copper salt and HCl create conditions when copper precipitates on the surface of aluminum and prevents formation of a dense Al2O3 therefore creating conditions for even faster reaction of copper-coated aluminum layer with copper salt. This in fact creates amplification conditions when tiny defects create reaction centers where precipitation of copper prevents formation of protecting Al2O3 layer and it further accelerates reaction with copper (2+) salt. Basically this amounts to amplification where tiny defects of the surface can be pinpointed.
The best conditions for such quality control method should be found experimentally. I would try not only increase but decrease in CuSO4 concentration as well.
Remember safety first! Check MSDS and consult with professionals before performing risky experiments.