Voltaic (Daniell) Cell: Zinc Oxidation Explained

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Discussion Overview

The discussion revolves around the oxidation of zinc in a Daniell cell setup, specifically addressing why zinc electrodes undergo oxidation spontaneously and the implications of this behavior in electrochemical reactions. The scope includes theoretical explanations, experimental observations, and questions regarding redox chemistry.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant argues that zinc oxidizes spontaneously, even in isolation, as evidenced by the thinning of the zinc rod in a zinc chloride solution.
  • Another participant questions the mechanism of electron transfer in the proposed setup and asks where the electrons would go in the absence of a reduction partner.
  • A further inquiry is made regarding the reliance on the Standard Hydrogen Electrode for measuring redox potentials, suggesting a need for clarity on why absolute measurements are not available.
  • Concerns are raised about the observation of isolated zinc and copper strips dissolving, with a request for clarification on the time frame of these observations.

Areas of Agreement / Disagreement

Participants express differing views on the oxidation of zinc and the conditions under which it occurs. There is no consensus on the mechanisms or implications of the observations made.

Contextual Notes

Some assumptions about the behavior of zinc and copper in electrochemical setups remain unaddressed, and the discussion highlights the complexity of measuring redox potentials without a clear standard reference.

Who May Find This Useful

Readers interested in electrochemistry, particularly those exploring redox reactions and the behavior of electrodes in various setups, may find this discussion relevant.

gracy
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Me and one of my friend had a discussion about daniell cell my friend raised a doubt why does zn electrode gets oxidised without any reason?I answered her because it is spontaneous reaction.even if you will take only zinc beaker and zinc rod dipped in it zinc will lose electrons this is marked while doing experiment as zinc rod becomes thinner and shorter.so it is not that copper half cell is connected that's why zinc loses electron even without copper zinc does http://so.it/ is to be noted that copper also loses electron when not connected with zinc but when gets connected with zinc by conducting wire zinc has greater oxidation potential as compared to copper (go through electrochemical series )so zinc wins and gets oxidized, as oxidation can not occur alone there has to be reduction so copper gets reduced .
.Am i right?
 
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Not trying to insult you, but your posts will be much easier to read if you refrain from posting one long sentence.

I have two questions for you assuming I understood your post.

1. In your hypothetical metallic zinc bar + ZnCl2 setup, where would the electrons go?

2. If you are correct in your assumptions, it may be expected that we can simply use half cells to do redox chemistry, measure currents and so on. Why then do we have no absolute measurements of redox potentials but instead rely on something like the Standard Hydrogen Electrode (SHE) arbitrarily set to zero for our tables of standard reduction potentials?
 
gracy said:
if you will take only zinc beaker and zinc rod dipped in it zinc will lose electrons this is marked while doing experiment as zinc rod becomes thinner and shorter.so it is not that copper half cell is connected that's why zinc loses electron even without copper zinc does http://so.it/
During your lab class you noticed some of the disconnected zinc rod disolved in zinc chloride solution? I doubt it. Maybe over a period of weeks some of it might.

You also saw some of the isolated copper strip dissolve away, too? Over what period of time did you observe this?
 
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Yanick said:
Not trying to insult you
There is nothing to feel insulted.
 

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