18.2 galvanic cells

• galvanic cells are used for spontaneous reactions
• a reducing agent causes other things to be reduced
• an oxidizing agent causes other things to be oxidized
• Zn(s) + Cu2+(aq) -> Zn2+ (aq) + Cu(s)

  • Zn is oxidized
  • Cu2+ is reduced
  • Zn is the reducing agent
  • Cu2+ is the oxidizing agent
• the anode is where oxidation occurs
• the cathode is where reduction occurs
• anode II cathode
• single line between phases
• electrodes first and last
• cannot create a cell without a solid metal electrode
• difference in electrical potential between the anode and cathode is called the cell voltage
• hydrogen electrodes have a potential of zero
• the standard hydrogen electrode is used as reference point to measure other voltages
• E° = standard reduction potential = voltage reduction rxn at standard conditions
• voltage is independent of amount