This preview shows page 1. Sign up to view the full content.
Unformatted text preview: um work that an electron can do is equal to its charge
times the difference in electrical potential though which it falls.
Standard reduction potential ( Ered ) : the voltage associated with a
reduction reaction at an electrode when all solutes present at 1 M
and all gases at 1 atm.
Standard potential ( Ered ) : a
measure electronmeasure of electron-pulling power of
a single electrode
Zn 2+ (aq) + 2e → Zn( s ) EZn2+ / Zn = −0.76V
Cu 2+ (aq) + 2e → Cu ( s ) ECu 2+ / Cu = +0.34V °
Ecell = Ecathode − Eanode In a voltaic cell, the electrodes pulling in opposite directions, so the
overall pulling power of a cell, the cell standard EMF, is the
difference of the standard potential of two electrodes. Standard Electrode Potentials
The reference half reaction: the reduction of H+(aq) to
H2 (g) under standard conditions.
Reduction Reaction 2 H + (aq,1M ) + 2e → H 2 ( g ,1atm) Standard condition
Ered ( H + / H 2 ) = 0V Standard hydrogen electrode (SHE) redox couple Standard Electrode Potentials
Standard Reduction Potentials (E°red ) is measured relative to the
standard hydrogen electrode (SHE). The standard emf
(E° ) of the cell
Ecell = Ecathode − Eanode
Ecell = 0.76V (-)Zn (s) | Zn2+ (1 M)...
View Full Document