Understanding Galvanic Cells: Zinc and Copper Electrodes Explained"

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In summary: So when a zinc electrode is dipped in a ZnSO4 electrolyte solution, some zinc atoms begin to get ionized, turning into positive ions and their electrons stay on the electrode, that's it?Yes, that's correct.Zinc ions and electrons are involved in a reaction after this, but at this point they are just going through the electrochemical process of being ionized.
  • #1
Entanglement
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What I know about galvanic cells is : zinc is the anode and copper is the cathode, zinc loses electrons and it turns into ions leaving its electrons on the electrode. While copper is the cathode it also loses electrons and turns into ions leaving its electrons on the electrode, but zinc has more tendency to form ions than copper
So the anode (zinc) becomes negatively charged with respect to the cathode, consequently electrons move from the anode to the cathode on connecting a conducting wire,
I don't understand why the atoms of the
Electrode are ionized in the first place and why are they placed in a solution of their own salts ?

Zinc and copper is just an example, I know that it can be other elements
 
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  • #2
ElmorshedyDr said:
I don't understand why are the electrons ionized

I don't understand it either.

You sure don't mean elements?
 
  • #3
Borek said:
I don't understand it either.
You sure don't mean elements?
It is a fast typing mistake I edited it
 
  • #4
I think you are putting horse behind teh cart.

We can explain why these reactions occur using energy considerations, ΔG=ΔH-TΔS, whatever, but it will only make things more complicated to understand at this stage.

Why don't you accept for now that we experimentally checked they react, and we are trying to explain observed phenomena?
 
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  • #5
Borek said:
Why don't you accept for now that we experimentally checked they react, and we are trying to explain observed phenomena?
I'm not asking for a complicated explanation!
 
  • #6
What is complicated in the fact we observed them to react?
 
  • #7
The observation is simple, and any scientific observation is so simple, I want to know the scientific explanation
 
  • #8
Why is zinc ionized ?
 
  • #9
See http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/echemcon.html

http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html

http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrolyt.html

Galvanic cells are based on electrochemical processes, namely oxidation and reduction reactions.

Please review these
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/redoxcon.html


The different elements have different affinities for electrons and different ionization potentials, which is just inherent in Nature. If one looks at the galvanic series, one notes that some elements preferentially attract electrons, while others preferentially lose electrons.

http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html#c3
 
  • #10
Astronuc said:
See http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/echemcon.html
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrolyt.html
Galvanic cells are based on electrochemical processes, namely oxidation and reduction reactions.
Please review these

http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/redoxcon.htmlThe different elements have different affinities for electrons and different ionization potentials, which is just inherent in Nature. If one looks at the galvanic series, one notes that some elements preferentially attract electrons, while others preferentially lose electrons.
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html#c3
I really appreciate your effort, but I still can't understand why both electrodes are ionized when they are placed in their own solutions
 
  • #11
ElmorshedyDr said:
both electrodes are ionized

What does it mean "ionized electrode"?
 
  • #12
Borek said:
What does it mean "ionized electrode"?
I mean some atoms of them get ionized

Some atoms begin to lose electrons and turn to ions, why does that happen when the electrode is placed in its solution
 
  • #13
Because that's required for the thermodynamical equilibrium.

As I wrote earlier - it can be explained using thermodynamics, or energy considerations, but I doubt it would be helpful, as it requires understanding things that you most likely have not heard of yet - so you will get just more confused. IMHO at this stage it is easier and better to just accept that's the way it is.
 
  • #14
Borek said:
Because that's required for the thermodynamical equilibrium.

As I wrote earlier - it can be explained using thermodynamics, or energy considerations, but I doubt it would be helpful, as it requires understanding things that you most likely have not heard of yet - so you will get just more confused. IMHO at this stage it is easier and better to just accept that's the way it is.
I'll accept for now that this happens to reach thermodynamical equilibrium, so this happens when ever an element is placed in its own solution ??
 
  • #15
In a way. It is most obvious for metals, for other elements chemistry is much more difficult to follow, as they don't necessarily create simple ions that could get into water - but yes, in general every element put into water will somehow get "ionized" and charged in the process.
 
  • #16
Borek said:
In a way. It is most obvious for metals, for other elements chemistry is much more difficult to follow, as they don't necessarily create simple ions that could get into water - but yes, in general every element put into water will somehow get "ionized" and charged in the process.
So when a zinc electrode is dipped in a ZnSO4 electrolyte solution, some zinc atoms begin to get ionized, turning into positive ions and their electrons stay on the electrode, that's it? Don't the zinc ions or the electrons get involved in any reaction after that before connecting a wire between the electrodes ??
 
  • #17
No, there is no further reactions before the current starts to flow.

That is, they can't be ruled out, for example when the solution is acidic enough to dissolve the Zn. But we assume solution was prepared in such a way side processes don't interfere.
 
  • #18
Borek said:
No, there is no further reactions before the current starts to flow.

That is, they can't be ruled out, for example when the solution is acidic enough to dissolve the Zn. But we assume solution was prepared in such a way side processes don't interfere.
Do the zinc ions form bonds with the negative oxygen atoms of water or does it form Zn(OH)2 with the free hydroxide negative ions?
 
  • #19
This is apropos of nothing, and I am FAR from the point where I'd argue with Borek about anything chemistry related. However, folks had a bit of a contre-temps over at Wikipedia when the terms "anode" and "cathode" got used in the lead-acid cell entry, and I thought I'd chime in:

The very terms anode and cathode are a little misleading when it comes to batteries, since it matters which side of the cell wall you're on. The "source" of electrons for the inside of the cell, is the sink for electrons outside of the cell. I tended to use the terms positive/negative + plate/electrode just to keep things clear.

Lastly, ElmorshedyDr: There's a pretty good wikipedia entry on the LeClanche Cell which has reactions akin to what you're discussing. Unless it directly contradicts Borek, maybe reading it would give a different perspective.

Yours in service,
 
  • #20
ElmorshedyDr said:
Do the zinc ions form bonds with the negative oxygen atoms of water or does it form Zn(OH)2 with the free hydroxide negative ions?

It is about freely floating Zn2+. For sure they are in the form of aqua complex, every cation in the solution is at least hydrated.
 
  • #21
Borek said:
It is about freely floating Zn2+. For sure they are in the form of aqua complex, every cation in the solution is at least hydrated.
Isn't there any chance you could shed some light on why Zn is ionized when placed in the solution, I'm sure you can explain in a simple easy way, because it's really bothering me.
I'll be so grateful
 

1. What is a galvanic cell?

A galvanic cell is an electrochemical cell that converts chemical energy into electrical energy. It consists of two electrodes, an anode and a cathode, which are connected by an electrolyte solution. When the electrodes are connected by a wire, a flow of electrons occurs, creating an electric current.

2. How does a galvanic cell work?

In a galvanic cell, chemical reactions occur at the anode and cathode. At the anode, oxidation occurs and electrons are released, while at the cathode, reduction occurs and electrons are gained. The flow of electrons through the external wire creates an electric current. The electrolyte solution allows for the transfer of ions between the two electrodes, completing the circuit.

3. What is the difference between a galvanic cell and an electrolytic cell?

The main difference between a galvanic cell and an electrolytic cell is the source of the electric current. In a galvanic cell, the electric current is generated by the spontaneous chemical reactions that occur at the electrodes. In an electrolytic cell, an external source of electricity is needed to drive the non-spontaneous chemical reactions at the electrodes.

4. How can I calculate the potential difference of a galvanic cell?

The potential difference, or voltage, of a galvanic cell can be calculated using the Nernst equation: Ecell = E°cell - (0.0592/n)logQ, where E°cell is the standard cell potential, n is the number of moles of electrons transferred, and Q is the reaction quotient. E°cell values can be found in reference tables, while Q can be calculated using concentrations of reactants and products.

5. How can I improve the efficiency of a galvanic cell?

To improve the efficiency of a galvanic cell, it is important to choose the right combination of electrodes and electrolyte solution. Using electrodes with a larger surface area can increase the rate of reactions and generate more electrical energy. Additionally, using a more concentrated electrolyte solution can also improve efficiency. Regular maintenance and cleaning of the electrodes can also help to improve the performance of a galvanic cell.

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