Shockingly%20Brief%20yet%20Rich%20History%20of%20electrochemistry

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Shockingly Brief yet Rich History of
electrochemistry

• Galvani frog legs1780
• Volta battery1800
• Davy- electrolysis1820

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Chemistry born from dead frogs

• Luigi Galvani nasce a Bologna nel 1737.
• Physiologist noticed legs of dead frogs twitched
  when his steel scalpel touched brass staples used
  pin down frog legs

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• Galvani thought he discovered animal electricity,

but he just found a delectable appetizer!
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Allessandro Volta (volt)

• Didnt buy Galvanis explanation
• Enjoying sticking 2 metals on his tongue, and got
  same twitching as frog legs
• Invented the pile, a.k.a battery

• More layers could be piled on to get higher
  voltages currents

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Voltas pile same 200 yrs later!

• Zn anode oxidation (-)
  Cu cathode reduction ()

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Electrochemistry under the hood
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Making a battery workPick 2 different metals

• Standard Reduction Potential (Eo)
• The metal that will act as the cathode, be
  reduced, gain electrons has the most positive
  potential (electrons flow to )
• Ag Eo .80
• Cu Eo .34
• Zn Eo -.76Al Eo -1.7

Example CuZn has Eo 1.1V (zinc is
oxidized so its Eo sign is reversed) Electrons
flow from negative Cu anode to positive Zn cathode
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Davy- cocky inventor of electrolysis

• Sir Humphry Davy
• Detested Gravy
• He lived in the odium
• there he discovered sodium

Only scientist besides Newton to be
knighted Contemporary of Volta, Ampere,
Gay-Lusaac, assistant was Faraday Discovered
many elements(Na,Ca,Mg,K,Ba,Sr) arc lamps,
laughing gas (N2O), water electrolysis, showed
oxidation need not oxygen,CO2
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Electrolysis- Davys Domain

• Volta 2 different metals produces current
• Davy - chemical reactions produce current
• Electrolysis- use a battery to drive even
• reverse reactions!
• almost any compound can be oxidized or
  reduced using the right voltage!

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Electrolytic cell

• non-spontaneous reactions (negative total
  potential) are possible using a battery
• Negative end of battery provides electrons so
  reduction can occur at the cathode (-)