LO 75 - 78 Flashcards
OIL - RIG
oxidation is loss, reduction is gain
_________ is an assigned number to each atom based on electron assignment used to ID redox reactions in nonmetals
oxidation states
oxidation state ____ ionic charge
≠
Oxidation state # = . . .
the “charge” it would have if all shared electrons were assigned to the more electronegative atom
Group 1A and 2A metals always have oxidation states of ___________
+1 and +2 respectively
Oxidation and reduction must occur together where the __________ oxidize other atoms and are themselves _________
oxidizing agents
reduced
To balance a redox reaction in both mass and charge use the ______________ method for aqueous solutions
half-reaction method of balancing
In an __________ cell, electricity can be generated from redox reactions
electrochemical
___________ cells produce a current from a spontaneous redox reaction
voltaic/galvanic
_________ cells consume a current to drive a nonspontaneous reaction
electrolytic
__________ are conductive surfaces through which electrons can enter and leave half cells
electrodes
The continual flow of e- requires a pathway for . . . and that pathway is commonly a _________
counterions to flow and neutralize charge buildup
salt bridge
Current in measured in _______
Amperes/Amps (A)
1 A = _______
1 Coulomb/second
Electrons flow in response to differences in ______________ thus creating current
electrical potential
Potential difference is measured in units of __________
Volts
1 Volt (V) = ___________
1 Joule/Coulomb
Increased potential difference means _________ tendency for electron flow
increased
In a voltaic cell, the potential difference between two electrodes is referred to as the __________
Cell Potential (E cell)
E cell of a voltaic cell depends on the . . .
tendency of the reactants to undergo oxidation or reduction
E°cell refers to . . .
a cell with components in standard state
Oxidation (loss of e-) occurs at the ______
anode
Reduction (gaining e-) occurs at the _____
cathode
In what direction do electrons in a cell flow?
anode to cathode
How do you notate an electrochemical cell?
Using line notation
- write the oxidation half reaction on the left using the atom being oxidized
- write the reduction half reaction on the right (both start with r!)
- separate components in different states with a vertical line
- separate components in the same states with a comma
The potentials of half cells cannot be . . .
measured directly
How is the potential of half cells calculated?
By comparison to the arbitrary zero seen in the standard hydrogen electrode (SHE)
How is E° cell calculated?
E° cell = E° cathode - E° anode
Which electrode in a half-cell will have a greater tendency to oxidize?
The electrode more in which E° cell is negatively charged relative to the SHE
Which electrode in a half-cell will have a greater tendency to be reduced?
The electrode in which E° cell is positive relative to the SHE
What happens to the value of E° cell for a half reaction multiplied by some constant?
E° cell is NOT changed
The half reaction with the more _________ electrode potential tends to oxidize. Thus, look for the reaction with the smallest E° value and assume it will proceed in the __________ direction
negative
reverse
If the overall E° cell is positive, then the reaction will be ___________
spontaneous
Most acids dissolve metals by the _________ of K+ ions to ________ gas and the corresponding _________ of metal into its ions
reduction
H2
oxidation
metals with a reduction half-reaction listed below the reduction of ___________ will dissolve in acid
H+ → H2
