Chemistry 123

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Chemistry 123

• Week of 25 February 2008

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(No Transcript)
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Table of Standard Reduction Potentials, V
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Electrochemistry national monuments

• The Statue of Liberty was originally constructed
  by covering a framework of iron ribs with thin
  sheets of copper. 
• Iron ribs lost half their mass
• Cu skin lost 4 of mass
• Why did the copper and iron in the statue have
  different rates of loss over the years?

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Check-in

• Without doing detailed calculations, determine
  which of the following voltaic cells has the
  highest concentration of Cu2.
• Zn(s) Zn2 (0.10 M) Cu2 (? M) Cu
  (s)              Ecell 1.06 V
• Zn(s) Zn2 (0.10 M) Cu2 (? M) Cu
  (s)              Ecell 1.15 V
• Zn(s) Zn2 (1.00 x 10-3 M) Cu2 (? M) Cu
  (s)    Ecell 1.15 V

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Concentration cells human nerves
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Alkaline battery
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Silver button battery
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Lead-acid storage battery
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Lead-acid storage battery
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Lithium ion battery (secondary)
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Energy from combustion
http//www.southerncompany.com/learningpower/power
info_powerplant.asp?mnuOpcosocomnuTypelpmnuIte
moc
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Flow cell
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Electrochemical cellsthe Breathalyzer
C2H5OH (g) O2 (g) ? CH3COOH (g) H2O (l)
When a suspect blows into the breathalyzer,
ethanol is oxidized to acetic acid at the anode
(basic conditions).  O2 is reduced to hydroxide
at the cathode. Half-reaction occurring at the
anode  Half-reaction occurring at the
cathode  E for cathode Ecell If the
C2H5OH lt 1.0 M and all other components are
present at 1.0 M, what happens to Ecell?