Redox Reactions and Electrochemistry Flashcards
Oxidation
loss of electrons
Reduction
gain of electrons
Oxidizing Agent
causes another atom to undergo oxidation and itself is reduced
Reducing Agent
causes another atom to undergo reduction and itself is oxidized
Galvanic Cells
Spontaneous
Electrolytic Cells
Nonspontaneous
Anode and Cathode Charges in Galvanic Cells
Anode: negative
Cathode: positive
Anode and Cathode Charges in Electrolytic Cells
Anode: positive
Cathode: negative
Oxidation ALWAYS at the:
ANODE
Reduction ALWAYS at the:
CATHODE
Reduction Potential
The tendency of a species to acquire electrons and be reduced
Standard Reduction Potentials
are used to calculate the standard electromotive force of a reaction, the difference in potential between the two half cells
emf=
emf = Ecathode - Eanode
Gibbs Free Energy in a Electrochemical Cell
ΔG = -nFEcell
Oxidation Number of a free element
0
Oxidation of a monatomic ion
equal to overall charge
Oxidation Number of Group 1A and 2A
+1 and +2
Oxidation Number of Group VIIA
-1 (unless paired with more EN element)
Oxidation Number of Hydrogen
+1 (unless paired with group 1 or 2)
Oxidation Number of Oxygen in a compound
-2
Plating/Galvanization
ions will precipitate onto the cathode
Faradays Constant
10 x 10^5 c/mole
Electrodeposition Equation
determines the number of moles of element being deposited on a plate:
mol M = It / nf
I: current
t: time
n: # electron equivalents
f: Faradays constant (10x10^5)
