How metals set up electrode potential in water or solution verification.

[tasnim rahman]

I found this article on the web, describing how metals set up electrode potential in water or solution. How I see it the whole explanation makes sense to me, but I am not sure if its the right explanation. Could someone verify this?

 

[AliAhmed]

The explanation, I must say, is very good. If you need any clarification at any particular point just reply.

 

[tasnim rahman]

I was wondering whether the WATER AND IONIZATION(page 9):...forces of ionization... part could be considered as correct. Thanks Ali, Ahmed.

 

[AliAhmed]

It is correct.

- The main cause of ionization is the first force:
The oxygen atom within the water molecule is more negatively charged than the rest of the molecule (there is a permanent dipole in the molecule). This causes the molecule to attract positively charged ions on the oxygen part of the molecule. The bonding in metals is neither ionic nor covalent (it has its own name, namely metallic bonding); the type of bonding encourages electrons to flow freely within the metal and these freely flowing electrons also act as a type of holding force for the positive ions in the metal (there is much more to it than what I'm explaining, but I'm just giving you the essentials). With this, it is more favorable for the positive metal ions to leave the surface (and attract to the oxygen part of the water molecule) rather than electrons.

- If the metal loses too many positive ions (the metal will have an excess of electrons), the overall effect would be to repel electrons from the surface which in turn may recombine with the metal ions in solution.
- If the metal is electron deficient, then the "holding force" is weak and metal ions are more easily removed from the surface by the oxygen side of the molecule.

- Please let me know if I answered your question (I am known to babble).

 

[tasnim rahman]

I thought similar, but wasn't sure, and needed someone to verify it. Probably the positive ions also dissolve with hydration spheres, similar to those found when ionic solids dissolve in water, with hydration energies, etc. involved. Thanks a lot for the verification, Ali, Ahmed.