LEO says GER
AN OX CAn'T REaD (anode = oxidation; cathode = reduction)
Copper/Zinc Galvanic cell:
http://www.ausetute.com.au/voltcell.html (nice little animation or just look below)
- chart on page 805 identifies Cu as more likely to be reduced (it's higher on the chart) Cu2+(aq) + 2e- --> Cu(s)
- Zn will be oxidized (Zn(s) --> Zn2+(aq) + 2e-
- Cu = cathode; Zn = anode
- Cu2+(aq) ions in solution will attach to the Cu eletrode as Cu(s)
- Zn(s) electrode will slowly dissolve creating Zn2+(aq) ions
- Salt bridge ions move to create electrically neutral solutions, soooo K+(aq) ions to copper solution (replacing Cu2+(aq) ions that left; Cl-(aq) ions move to electrical neutralize the added Zn2+(aq) ions)
- electrons flow to the copper electrode (afterall, the copper ions are being reduced GER!)
- standard cell notation Zn(s)|Zn2+(aq)||Cu2+(aq)|Cu(s)
- overcell reaction shown below
Cathode: Cu2+ + 2e ---> Cu Eo = +0.34V
--------------------------------------------------------------------------------
Cell: Zn + Cu2+ ---> Zn2+ + Cu Eocell = +1.10V (0.34V- (-0.76V))
(V used values agree with Nelson text)
The following site also gives a nice overview of the galvanic cell. There a few sample questions (with answers) on the site as well.
http://www.science.uwaterloo.ca/~cchieh/cact/c123/battery.html
And now for something unrelated to elctrochemical cells: Q: Are polar bears expensive to keep as pets? A: NO! They live on ice! [Such a cool joke, eh?]
