Things to know about... Galvanic Cells

The Basics

• Oxidation occurs at the anode which is the negative terminal

• Reduction occurs at the cathode which is the positive terminal

• Electrochemical cells can be represented by a cell diagram.
  • | represents a phase boundary

  • || represents a salt bridge

  • the anode electrode is written first

  • the cathode electrode is written last

  • Sample: Zn(s)|Zn2+(aq)||Cu2+(aq)|Cu(s)

Some Useful Equations

The electrochemical series

• Find cathode and anode reactions on the table of standard reduction potentials

• Cnage the sign of the cell potential for the anode

• Do NOT multiply the cell potentials, even if the number of electrons in each half-reaction is unequal

• DO multiply the half-reactions to equalize the number of electrons (if necessary) to balance the overall reaction

• Find E(cell) = E(anode) + E(cathode) (standard conditions for all) If E(cell,standard conditions) is greater than O volts, the reaction is spontaneous, as written

• May have more than one species in the half reaction (i.e. MnO₄), just cary them along

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