Quiz 5 – Chemistry

Flashcard maker : Judith Simpson
oxidized
lose electrons
reduced
gain electrons
Oxidation number during oxidation
increases
oxidation number during reduction
decrease
half reaction electrons during oxidation
electrons are products
half reaction electrons during reduction
electrons as reactants
oxygen during oxidation
oxygen added
oxygen during reduction
oxygen lost
Rule 1: oxidation state of free elements
0
Rule 2: oxidation state of monatomic ions
equal to their charge
Rule 3: sum of atoms oxidation states in a compound
equal zero
Rule 4a: Group I metals have an oxidation state
of +1 in their compounds
Rule 4b: Group II metals have an oxidation state
of +2 in their compounds
Rule 5: nonmetals
nonmetals have oxidation
states according to the table, F=-1,H=+1, O=-2, group 7a=-1, group 6a=-2,group 5a=-3
reducing agent
reactant that reduces an element in another reactant, contains the element that is oxidized
oxidizing agent
reactant that oxidizes an element in another reactant, contains the element that is reduced
Anode electrode
where oxidation occurs
loses weight
positive end of battery
attracts anions
Cathode electrode
where reduction occurs
attracts cations
negative end of battery
gains weight
where plating takes place
1Amp (current) = 1 Coulomb of charge =
1 A = 6.242 x 10^18 electrons per second?
1 volt
1 J per Coulomb of charge
electromotive
forcel
Amount of force pushing the electrons
through the wire
cell potential
difference in potential energy between the
anode and the cathode in a voltaic cell

standard emf, Eocell

inert electrode
does not participate in
reaction, but just provides a surface
half-reaction with a strong tendency to occur
large positive half-cell potential
how electrons will flow when two half-cells are connected
half-reaction with the stronger
tendency will occurire
standard hydrogen electrodels =
= 0 v
stronger tendency toward
reduction than the SHE
+ value for Ered
stronger tendency toward
oxidation than the SHE
– value for Ered
For oxidation half-reaction
Eoxi = – Ered
Ecell =
Eoxidation + Ereduction
spontaneous reactionion
Free energy change
G < 1 (negative)
E > 1 (positive)
K > 1
G= -RTlnKB=
=-nFEcell
free energy change (G^o)=
=G + RTlnQ
E =
E^o -(0.0592/n)logQ
Concentration Cellsnion
Electrons will flow from the electrode in the less
concentrated solution to the electrode in the more
concentrated solution
ElectrolysisTlnQ
using
electrical energy to break
a compound apartrire
Corrosion
spontaneous oxidation of a metal
by chemicals in the environmentl
Rust
Fe2O3*nH2O;B
Rust
Fe2O3*nH2O;B

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