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Published byCleopatra Wells Modified over 9 years ago
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Shockingly Brief yet Rich History of electrochemistry Galvani – frog legs~1780 Volta – battery~1800 Davy- electrolysis~1820
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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) Didn’t buy Galvani’s 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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Volta’s 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 work: Pick 2 different metals Standard Reduction Potential (E o ): -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= -.76 Al+++ Eo= -1.7 Example: Cu|Zn has Eo = 1.1V (zinc is oxidized so it’s 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 (N 2 O), water electrolysis, showed oxidation need not oxygen,CO 2
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Electrolysis- Davy’s 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 (-)
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