Standard Cells

1
Standard Cells Cell Potential
2
Standard Cells

• Standard cell Galvanic cell at SATP with 1.0
  mol/L solutions
• Standard cell potential (?E) Maximum electric
  potential difference of a standard cell
• Standard reduction potential (?Er) Ability of a
  standard half-cell to attract electrons in a
  reduction half-reaction
• ?E ?Er - ?Er
• cell cathode anode
• By convention, hydrogen is chosen as a reference
  half-cell and is assigned a ?Er of 0 to be used
  to determine ?Er of all other half-cells

3
Calculating Cell Potentials

• Although you might multiply the half-reactions by
  a coefficient to balance the electrons, do NOT
  multiply the ?Er value
• ?E gt 0 indicates a spontaneous reaction, a
  requirement of galvanic cells
• E.g. Determine the standard cell potential for a
  galvanic cell in which the following reaction
  occurs
• Zn(s) 2AgNO3(aq) ? Zn(NO3)2(aq) 2Ag(s)
• http//group.chem.iastate.edu/Greenbowe/sections/p
  rojectfolder/flashfiles/electroChem/voltaicCell20.
  html

4
Electrolytic Cells

• ?E lt 0, nonspontaneous
• Requires an external battery or power source
• Electrolysis is the process of supplying
  electrical energy for a nonspontaneous reaction
  to occur
• Some applications Rechargeable batteries,
  production of elements, electroplating

5
Practice

• p. 708 10-12
• p. 709 2, 6-8
• Review
• p. 725 1-7, 10-14
• p. 726 1-12, 14-16, 22