Electrochemistry Flashcards
Electrochemistry
The study of the relationships between chemical reactions and electrical energy
Electrochemical cells
Contained systems in which a redox reaction occurs
Anode
Electrode where oxidation occurs
Cathode
Electrode where reduction occurs
Galvanic cell
Spontaneous reaction
Negative delta G
Supply energy, used to do work
Electrons flow from anode (-) to cathode (+)
Salt bridge
Semipermeable membrane, inert electrolyte permits exchange of cations and anions between two cells to dissipate the charge build up at the electrodes
Cations flow to cathode, anions flow to anode
Cell diagram
Shorthand notation representing the reactions in an electrochemical cell
Electrolytic cell
Nonspontaneous reaction
Positive delta G
Electrical energy required to induce reaction
Electrons flow from anode (+) to battery to cathode (-)
Electron charge
1.6 x 10^-19 C
Faraday constant
96487 C/mol e- or J/V
The amount of charge in one mole of electrons
i x t = n x F
The number of moles of electrons transferred by an electrochemical cell
Reduction potential
The tendency of a species to acquire electrons and be reduced.
The most positive = greater tendency to be reduced
Standard hydrogen electrode (SHE)
An arbitrarily given potential of 0 V
Standard reduction potential
Measured under standard conditions
Higher E = greater tendency for reduction
Standard electromotive force (emf of Ecell)
The difference in potential between two half-cells
Ecell = Ered + Eox
