Chem Lecture 7

Front 1

oxidation state of F

Back 1

+1
except when bonded to a metal - then -1

Front 2

oxidation state of atoms in elemental form

Back 2

0

Front 3

electric potential of redox reaction

Back 3

due to fact that electrons are transfered/move

half reaction potentials are listed as reduction potentials
(reverse sign for oxidative potential)

assigned based upon arbitrary assignment of zero for 2H+ + 2e- -->H2 (E*=0V) (memorize!!)

high reduction potential = easily reduced

to find potential of a reaction, add up half reactions BUT dont multiply by number of times occur bc INTENSIVE

note: O2 + 4H+ -->H2O has strong reducing potential - why O2 accepts e- from ETC chain!!

Front 4

galvanic cell

Back 4

aka voltaic cell
turns chemical E into electrical E

all phases must conduct electricity, but at least one must be impermeable to e- = ionic conductor carrying current = SALT BRIDGE

emf is electric potential difference between Terminals

terminals-electrodes-ionic conductor

two electrodes (anode = oxidation rxn, cathode= reduction rxn) RED CAT AN OX

Front 5

standard state cell potential

Back 5

sum of standard state potentials of corresponding half reactions

always positive because always has chemical energy that can be converted to work

Front 6

salt bridge

Back 6

necessary when cell contains 2 different solutions - to separate solns, so cell wont short circuit

balances charge
therefore cations to cathode bc cations being taken out of soln on one side so need cations into soln to balance

typically made from KClaq

Front 7

IUPAC conventions for galvanic cell

Back 7

Reduction is on the Right

Front 8

concentration cell

Back 8

a reduction half reaction taking place in one half cell and exact reverse of that half reaction taking place in other half of cell

must have diff concentrations of soln in order to create potential