Voltaic (Daniell) Cell: Zinc Oxidation Explained

[gracy]

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?

 

[Yanick]

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?

 

[NascentOxygen]

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?

 

[gracy]

Not trying to insult you

There is nothing to feel insulted.

 

[LudusRex]

Yes, you are correct. In a Voltaic (Daniell) cell, zinc is more reactive than copper and therefore has a greater tendency to lose electrons. This is because zinc has a higher oxidation potential than copper, as shown in the electrochemical series. When the zinc electrode is placed in the zinc sulfate solution, it will spontaneously undergo oxidation, losing electrons and forming zinc ions in the solution. This is a spontaneous reaction because the zinc electrode has a higher tendency to lose electrons compared to the copper electrode. When the two electrodes are connected by a conducting wire, the electrons flow from the zinc electrode to the copper electrode, resulting in a flow of current and the production of electricity. So, the reason why zinc gets oxidized in a Daniell cell is because of its higher oxidation potential compared to copper.