Battery Water Electrolysis

• How do the electrons flow through a voltaic cell (i.e., a battery)?
• Why is a salt bridge necessary?  What types of salt solutions are most useful within salt bridges? (What's the most important characteristic of these solutions?)
• What is the difference between an anode and a cathode?
• Where does the oxidation and reduction occur in a battery? 
  How is the redox half-cell related to both the flow of electrons and the cathode and anode?

http://ts2.mm.bing.net/th?id=HN.608000875050765589&pid=15.1&P=0

In spontaneous oxidation-reduction reactions, electrons are transferred and energy is released. If electrons flow through n external device energy is produced. Electrons only spontaneously flow from higher to lower potential energy. The salt bridge is a U-Shaped bridge to keep the balances charged. The cations move towards the cathode and the anions to the anode. An anode produces oxidation, while the cathode produces reduction. The redox half cell related to both the flow of electrons and the cathode and anode. The strongest oxidizer has the most positive reduction potentials and the strongest reducers have the most negative oxidizers. The greater the oxidation difference the greater the U.

For more information about Voltanic cells visit:

http://chemwiki.ucdavis.edu/Analytical_Chemistry/Electrochemistry/Voltaic_Cells