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Voltaic (Daniell )cell

  1. Jan 10, 2015 #1
    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/ [Broken] 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?
    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Jan 10, 2015 #2
    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?
  4. Jan 10, 2015 #3


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    Staff: Mentor

    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?
    Last edited by a moderator: May 7, 2017
  5. Jan 10, 2015 #4
    There is nothing to feel insulted.
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