Understanding the Dissolution of Zinc in a Galvanic Half-Cell

[Slava]

In a standard galvanic half-cell when Zinc rode is placed into the Zinc sulphate. What is the reaction which makes zinc to dissolve and fell into the solution. Why do electrons move away from the sides of the electrode? Are they repelled by the solution or by other ZN atoms on the electrode which haven't been ionized yet?

 

[Simon Bridge]

Have you seen:
http://www.ibchem.com/IB/ibnotes/full/red_htm/9.4.htm
Also revise "redox reactions".

 

[Slava]

From the link which you posted it is said that: In this cell the zinc metal has a tendency to dissolve as ions leaving its electrons on the electrode.

I can't get the order: whether it is Reaction with the solution which causes electrons to fly away from Zn metal, or it is the attraction from the positive electrode which attracts loosely bound Zn electrons and as soon as Zinc start lacking electrons it will become Zn2+ and mix with the solution. If it is the latter case then when the electrodes are not connected will there be an excess of electrons on the negative terminal of the battery

This is what is unclear for me. I understand how the redox reaction works but I can't understand how the half-redox reaction works.

Thank you for your response.

 

[Slava]

The electrodes themselves must be electrically neutral and thus there will be no voltage? Am I right?

 

[Simon Bridge]

The electrodes don't have to be electrically neutral, and generally won't be - the webpage gives example reaction relations.
So how do you understand redox reactions working?

 

[Slava]

In redox reaction one atom loses electrons and another atom gains electrons.
Is it possible for a redox reaction to occur just by simply placing atoms of zinc and copper together or we need to have an oxidizing/reducing agents for this to happen?

 

[Slava]

My question is. Will the following reaction happen if there was no solution.
Zn(s) + Cu2+(aq)

Zn2+(aq) + Cu(s)
I suspect there should be some energy given off which will make electrons pop from the Zn nucleus. Is the attraction between the positively charged Copper ion and Zn atom is enough to make them move??

 

[Slava]

From Wikipedia:
metallic zinc at the surface of the zinc electrode is dissolving into the solution
Can you explain what makes them dissolve into the solution? The solution is just a mix of Zn2+ and SO42-. Do Zn atoms react with Zn2+ or S042- ?