Shockingly Brief yet Rich History of electrochemistry Galvani – frog legs~1780 Volta – battery~1800 Davy- electrolysis~1820

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

Galvani thought he discovered animal electricity, but he just found a delectable appetizer!

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

Volta’s pile ~ same 200 yrs later! Zn anode oxidation (-) Cu cathode reduction (+)

Electrochemistry under the hood

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

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

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!

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 (-)