Voltaic Cell behaviour as described in this video

In summary, the Copper half-cell will act as if there is no connection between the electrodes and the Cu2+ ions in the solution will be reduced.
  • #1
cianfa72
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TL;DR Summary
Voltaic cell behavior with no external connection
Hi,

googling for Voltaic cell I found this video about it. At minute 2:35 to 2:54 you can see that, without any electrical conductor connected between electrodes, in the Copper half-cell the metal electrode (Cathode) gets an amount of negative charges (electrons). Basically what described there is that Copper atoms oxidize passing in solution as Cu++ cations loosing electrons inside the Copper electrode.

As far as I Know actually, at least when an external connection is in place, the opposite reaction (Copper ions reduction) should take place at the Cathode electrode.

Do you think that video is correct ? Thanks.
 
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  • #2
If there are no copper ions on the solution, can they get reduced? Or are the options of in which direction reaction can proceed limited?
 
  • #3
Borek said:
If there are no copper ions on the solution, can they get reduced? Or are the options of in which direction reaction can proceed limited?
As explained in the video each electrode is dipped in its ions solution (Zinc solfate and Cupric solfate respectively).
And yes we are interested in the initial direction of the reaction at Copper half-cell.
 
  • #4
At first I concentrated on the part you listed, now I started from the beginning. Don't worry about this video, it is poorly thought and simplifies things beyond recognition.
 
  • #5
ok, thus can you confirm that, at least initially, reaction proceed at the Copper half-cell such that copper cations in solution get reduced resulting in slightly positively charged Copper rod (assuming no external connection between electrodes)?
 
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  • #6
That's definitely what I expect would happen.

That is, assuming the idealized case in which rod - when immersed - had no initial charge.
 
  • #7
I think it is unnecessary and not very helpful to invoke charge separations.
A Zn atom "wants to" transfer two of its electrons to Cu2+
It will do so if it is in contact, as seen this video

(and others, some more confusing).
And it will do so even if not in direct contact but via conductivity as in the galvanic cell, as long as there is a return pathway for electrons which is provided by the salt bridge.
 
  • #8
Without charge separation there is no potential difference, so you can't ignore it without ignoring physics.
 

Related to Voltaic Cell behaviour as described in this video

1. How does a voltaic cell work?

A voltaic cell works by converting chemical energy into electrical energy through a redox reaction. This reaction involves the transfer of electrons from the anode (where oxidation occurs) to the cathode (where reduction occurs), creating a flow of electrons and producing a current.

2. What factors affect the behaviour of a voltaic cell?

The behaviour of a voltaic cell can be affected by several factors, including the types of electrodes and electrolytes used, the concentration of the electrolyte solution, and the temperature of the cell. These factors can impact the rate of the redox reaction and the overall efficiency of the cell.

3. What is the purpose of the salt bridge in a voltaic cell?

The salt bridge in a voltaic cell serves as a pathway for ions to flow between the anode and cathode compartments, completing the circuit and allowing for the continuous flow of electrons. It also helps to maintain electrical neutrality within the cell by preventing the buildup of excess charge on either electrode.

4. How does the voltage of a voltaic cell change over time?

The voltage of a voltaic cell will decrease over time as the concentration of reactants decreases and the cell reaches equilibrium. This is because the redox reaction will slow down as the reactants are used up, resulting in a decrease in the flow of electrons and a decrease in voltage.

5. Can a voltaic cell be recharged?

No, a voltaic cell cannot be recharged. Unlike a rechargeable battery, the chemical reactions in a voltaic cell are not reversible, meaning that once the reactants are used up, the cell cannot be recharged. Instead, a new set of reactants must be added to the cell in order for it to continue producing electricity.

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