Exam III Flashcards
Cu->cu2+ and 2e-
Oxidation
2(AG+ + e-)-> 2 AG
Reduction
Reduction
Gain of electrons
Oxidation
Loss of electrons
Cathode
Where reduction happens
Anode
Where oxidation occurs
dG=-nFE
N-number of transferred
F-96500 c/mol
E- potential
Standard reduction potential
Ecell=Eright-Eleft
Potentiometry
measure potential and relate to concentration by nernst equation
Potentiometry
measure potential and relate to concentration by nernst equation
ref electrode II soln I indicator electrode
Reference electrodes
Calomel-Hg I Hg2Cl2, KCl II
E=0.2444
Silver silver chloride electrode- Ag I AgCl, KCl II
E=0.199
Membrane electrodes
glass electrodes
liquid membrane electrodes
crystalline membrane electrodes
gas sensing probes
glass electrodes
ref electrode II external analyte soln I glass membrane I internal ref soln of known [], Cl-, AgCl I Ag
charge difference creates potential across membrane
H+, Li+, Na+, Nh4+
liquid membrane electrode
like glass but polymeric ion exchange; Ca2+, Cl-, NO3-, ClO4-, K+
crystalline membrane electrode
solid crystalline materials; Br-, Cd2+, Cl-, Cu2+, CN-, F-, I-, Pb2+, Ag+, S2-, SCN-