How cathode is positively charged in voltaic cell?

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Discussion Overview

The discussion centers around the nature of the cathode in a voltaic cell, specifically addressing why it is considered positively charged despite being the site of reduction where electrons are gained from the anode. Participants explore concepts related to electrical neutrality, potential differences, and the conventions used in describing electrode behavior.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants question why the cathode is considered positively charged when it gains electrons from the anode during reduction.
  • Others argue that the cathode is not positively charged in an absolute sense, suggesting that everything in nature is electrically neutral and that the terms are used for conceptual clarity.
  • A participant introduces the idea that the cathode can be viewed as an electron source in the context of its function within the cell.
  • There is a discussion about the potential of the cathode being higher than that of the anode, with some participants seeking clarification on what "higher potential" means in this context.
  • Some participants note that the potential energy of electrons at the cathode is higher than that of oxidized species approaching it, while others question how this relates to the materials of the electrodes.
  • There is a mention of the arbitrary nature of choosing to consider reduction potential over oxidation potential, with participants discussing the implications of this choice on the understanding of electron flow.
  • Participants explore the role of ions in completing the circuit via a salt bridge, with some clarifying that charge carriers can move due to factors beyond electric fields, such as density gradients.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the cathode's charge and the conventions used to describe electrode behavior. There is no consensus on the interpretation of potential differences or the implications of oxidation versus reduction potential.

Contextual Notes

Participants highlight the importance of context when discussing potential differences, noting that without a reference point, terms like "higher potential" can be ambiguous. The discussion also touches on the complexity of charge carrier movement, which may depend on various factors beyond simple electric fields.

  • #61
Drakkith said:
I'm sorry but this is just wrong.
They don't. Electrons have a negative charge, protons have a positive charge, and neutrons are electrically neutral. You're replying to a bad answer.
The electrons that flow into the cathode are used in the chemical reaction between the cathode and the electrolyte. They are indeed 'lost' from the cathode in this reaction.

What I actually meant was that the electrons that reach at the electrode get consumed and the negative charge doesn't linger on . In totality , everything is neutral . The electrolytic cell in whole is neutral . The cathode is not charged but as you said , the action of loss of electron makes us call it positive electrode .
 
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  • #62
proton007007 said:
The cathode is not charged

It is. If it wasn't charged there would be no potential difference between cathode and anode.

Charge is typically pretty small, but it definitely is there.
 

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