Term
anode vs. cathode
flow of current vs. flow of electrons |
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Definition
oxidation vs. reduction
cathode to anode vs. anode to cathode |
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Term
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Definition
the voltage or electrical potential difference of an electrochemical cell
+ emf = -ΔG
- emf = +ΔG |
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Term
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Definition
| house spontaneous reactions with a positive emf |
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Term
In a cell diagram which is the anode/cathode?
What do the lines denote?
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Definition
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Term
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Definition
| nonspontaneous reaction with negative emf; half reactions are not separated; commonly used in industry |
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Term
| What is Faraday's constant and what does it represent? |
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Definition
| 105 C/mol e- ; represents the charge contained in one mole of electrons |
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Term
| What is the electrodeposition equation and what does it mean? |
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Definition
mol M = It/(nF)
mol M is the amount of metal ion being deposited at an electrode
I is current
t is time
n is the number of electron equivalents for a specific metal ion
F is the Faraday constant |
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Term
| What are the distinguishing features of a concentration cell? |
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Definition
| It is a specialized galvanic cell in which the electrodes are chemically identical. The current is generated as a function of the concentration gradient established between the two solutions surrounding the electrodes. |
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Term
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Definition
act as voltaic and electrolytic cells; as they discharge they act voltaic and as they recharge they act electrolytic
Examples are nickel-cadmium and lead-acid batteries |
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Term
| What equation relates Gibbs free energy and emf? |
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Definition
ΔGo = -nFEocell
G is the standard change in free energy
n is the number of moles of electrons exchanged
F is the Faraday constant
E is the standard emf of the cell |
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Term
In electrolytic and voltaic cells what charge is the anode and cathode designated in each instance?
What way do electrons flow?
Where do oxidation and reduction occur? |
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Definition
- In voltaic cells the anode is negative and the cathode is positive. In electrolytic cells it is the opposite.
- Electrons always flow away from the anode.
- Anode is always oxidation and cathode is always reduction.
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