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UNIT 20 Electrochemistry - Coggle Diagram
UNIT 20 Electrochemistry
Balancing Redox (in sol)
- Balance everything except for O's and H's
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- Add electrons to balance charges
First, isolate half reactions, then...
- Multiply equations to reach same # of electrons for both
- Cancel terms, and add OH- for each H+ if in basic solution
NOte: don't forget ions, especially if you have to multiply them to balance... charges change too
Ered calculations
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AMOUNT OF MOLES OR MULTIPLES OF THE EQUATIONS DOESN'T MATTER! Reduction potential is not extrinsic, it is intrinsic
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Voltaic cells
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Two electrodes submerged in solutions, with a salt bridge attaching tem
Electrons flow towards higher (more positive) reduction potential, which is cathode... ions get added to solid
Electrons flow FROM anode, which gets oxidized and ions come off of electrode
Cations from salt bridge move to replace positive charges (to cathode) and anions flow to cancel out new cations (anode)
Nernst, dG
dG = -nFE
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F = faraday's constant, coulombs in a mole of electrons (96485)
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E = E` - (RT/nF)*lnQ
Basically states that as product moles increase, E decreases, and as reactant increases, E is increased