Electronics type wants advice for this.

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Discussion Overview

The discussion revolves around a DIY electroplating process using a copper sheet, a tin/lead bar, and saltwater. Participants explore the chemical reactions involved, the safety concerns regarding gas emissions, and the properties of the resulting materials.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant describes their method of electroplating copper using a tin/lead bar and saltwater, noting the appearance of hydrogen gas and a white precipitate at the bottom of the bucket.
  • Another participant explains the electroplating process, emphasizing the need for copper ions in solution and the potential for chlorine gas production when using salt.
  • Concerns are raised about the toxicity of lead hydroxide as a possible precipitate due to the lead in the anode.
  • Some participants discuss the implications of producing hydrogen gas and its potential use in generating electricity.
  • There is a mention of the advantages of tin plating copper to prevent corrosion when in contact with aluminum.
  • One participant expresses skepticism about the practicality of using the setup for a water-powered car, while acknowledging the novelty of adding salt to enhance conductivity.
  • Another participant questions the educational focus on thermodynamics in relation to the discussed processes.

Areas of Agreement / Disagreement

Participants express a range of views on the safety and effectiveness of the electroplating method, with some concerns about gas emissions and the nature of the precipitate. There is no consensus on the implications of the process or the safety of the gases produced.

Contextual Notes

Participants note various assumptions about the chemical reactions occurring, the safety of the gases produced, and the implications of using different materials in the electroplating process. The discussion includes unresolved questions about the nature of the white precipitate and the efficiency of hydrogen production.

Video Eddie
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Thought I might ask the pros here.

I found it difficult to buy tin plated copper and so I took a copper sheet, put it in distilled water with a bar of tin / lead and ran current through it. (anode was in tin / lead bar) The results were amazingly good. Looked like a professional job and I only used a bucket.
I needed to add a handful of table salt to the bucket to get the water to conduct well.

My first question is, someone said I might release chlorine gas, but I used distilled water and so I don't think it is true, at least I am not dead yet.

Second is, It appears to release huge amounts of Hydrogen with the salt in the water making it more conductive. Useful amounts? Any ideas?

Third question is, what the heck is that white stuff at the bottom of the bucket?
 
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What you want is to apply a current to take electrons from the copper anode (letting copper ions dissolve there) and help other copper ions recombine on (and coat) the cathode.

For electroplating to work quickly, one thing you will need is plenty of copper ions in solution (rather than waiting on diffusion). I imagine one way to achieve this might be to add acid (which initially liberates some hydrogen and dissolves metal).

Another thing that can happen is electrolysis of water. At the anode you get water molecules also being stripped of charge, increasing hydrogen ions in solution and releasing oxygen gas. At the cathode you get hydrogen gas (in exactly twice the volume of the oxygen). (Although, with the copper anode to dissolve, you might not get the oxygen gas..)

But since you added salt (NaCl), another thing that can happen at the anode is for all those dissolved chlorine ions to be converted into poisonous gas. (I can't see Na+ leaving the solution, since sodium reacts with water. I know NaOH is white, but I also can't imagine it precipitating out, since that would suggest extremely low pH.. ) Wikipedia advises using bicarb soda instead of salt, to avoid chlorine gas (but says you'll get a blue and green, not white, mix of copper hydroxide and copper carbonate).

So, what's white? You said you had distilled water, so it can't be impurities... Did you say you put lead (!) and tin into the solution? sa.. this is such a Chemistry question...
 
cesiumfrog said:
What you want is to apply a current to take electrons from the copper anode (letting copper ions dissolve there) and help other copper ions recombine on (and coat) the cathode.

For electroplating to work quickly, one thing you will need is plenty of copper ions in solution (rather than waiting on diffusion). I imagine one way to achieve this might be to add acid (which initially liberates some hydrogen and dissolves metal).

Another thing that can happen is electrolysis of water. At the anode you get water molecules also being stripped of charge, increasing hydrogen ions in solution and releasing oxygen gas. At the cathode you get hydrogen gas (in exactly twice the volume of the oxygen). (Although, with the copper anode to dissolve, you might not get the oxygen gas..)

But since you added salt (NaCl), another thing that can happen at the anode is for all those dissolved chlorine ions to be converted into poisonous gas. (I can't see Na+ leaving the solution, since sodium reacts with water. I know NaOH is white, but I also can't imagine it precipitating out, since that would suggest extremely low pH.. ) Wikipedia advises using bicarb soda instead of salt, to avoid chlorine gas (but says you'll get a blue and green, not white, mix of copper hydroxide and copper carbonate).

So, what's white? You said you had distilled water, so it can't be impurities... Did you say you put lead (!) and tin into the solution? sa.. this is such a Chemistry question...

I called the tin / lead bar the anode because I made it positive electrically. The cathode was the copper foil. I used tin / lead since it is commonly used as solder and was available. I tried tin / silver and it works the same.

Bubbles occurred at an alarming rate at the copper cathode. It was like I had alka-seltzer in the water.

I did breath the fumes from this and am still alive so there was no chlorine gas. However, the oxygen or hydrogen from the copper plate was huge in volume. I was thinking about trying to burn it directly in a turbine of some sort to see if I could get more electricity out than what I was putting in, just for kicks and giggles.

However, the white stuff really filled the bottom of the bucket.
 
Video Eddie said:
I did breath the fumes from this and am still alive so there was no chlorine gas.

That was inconclusive, and dumb.
 
Wait, you applied a negative voltage to the copper? That explains the lack of colour. I misread earlier and thought you were trying to coat things in shiny copper, not produce tin plated copper - what is the advantage of that anyway?

If you have lead in your anode, you can bet the precipitate is lead hydroxide (and probably toxic too). Now, the bubbles at the cathode should indeed be hydrogen, and if all that hydroxide keeps precipitating out then I could believe that chlorine production would slow.

Hydrogen gas is of course dangerous too (eg. can be highly explosive), but if you do try to extract power from it... well, if you're willing to consider other processes that take some kind of fuel (like petrol, or some refined metal alloy bar) and leave some different kind of waste (not entirely unlike your precipitate), then you can definitely come away with excess electricity (eg. your car alternator produces more than it needs to charge the starter-motor battery).
 
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cesiumfrog said:
Wait, you applied a negative voltage to the copper? That explains the lack of colour. I misread earlier and thought you were trying to coat things in shiny copper, not produce tin plated copper - what is the advantage of that anyway?

If you have lead in your anode, you can bet the precipitate is lead hydroxide (and probably toxic too). Now, the bubbles at the cathode should indeed be hydrogen, and if all that hydroxide keeps precipitating out then I could believe that chlorine production would slow.

The advantage of tin plating the copper is that it will not corrode when placed against aluminium. That is why it it tin plated.

Now the fact that it produces hydrogen in massive amounts, better than using plain water is just a plus. Enough to produce enough electricity to keep the reaction going and some extra would be a real breakthrough for a water powered car. I doubt this since someone surely would have thought of this by now, but then I see this kinda stuff happening all the time. Someone might have never tried to add salt to make the water more conductive before. So I just wonder if it makes enough to burn and sustain the electrical power to make the reaction work. A five gallon bucket took about 15 watts to plate a 3 foot X 1 foot plate in about 10 mins. How much hydrogen, I don't know but there was lots.
 
Why aren't they teaching kids thermodynamics?
 

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