6.9 electrochemistry Flashcards
what are the energy conversions in a galvanic cell?
converts chemical energy from spontaneous redox reactions to electrical energy
what are the energy conversions in an electrolytic cell?
uses electrical energy to drive non-spontaneous redox reactions
what is the cell notation acronyms for galvanic cell?
EROSORE
what are the polarities of the cathode and anode for galvanic cells?
cathode is positive, anode is negative
define standard cell potential (Ecell)
standard cell potential is the maximum potential difference between two half cells under standard conditions
define standard electrode potential (E)
standard electrode potential of a half-cell is the electromotive force between the half-cell and standard hydrogen electrode, measured at standard conditions
which sign is oxidation and reduction?
more positive more likely to be reduced, more positive more likely to be oxidised
how to calculate Ecell?
Ecell = Ecathode - Eanode
how to use Ecell to predict spontaneity of reaction?
Ecell > 0 : spontaneous
Ecell < 0 : non-spontaneous
Ecell = 0 : dynamic equilibrium
what factor affects E of half equation?
concentration, position of equilibrium shifts to favour oxidation or reduction
what is the relation between Ecell and G?
G = -nFEcell where n is the number of moles of electrons transferred and F = 96500 Cmol-1
what are the polarities of the electrodes in electrolytic cells
cathode is negative, anode is positive
what are the factors affecting which substance is oxidised/reduced?
- position of ions in the redox series, E
- relative concentration of ions in the electrolyte
- nature of electrodes
what are the equations related to stoichiometry of electrochem?
Q=It, Q=nF
