Electrolysis & CoulometryAssoc. Prof. Dr. Jaroon JakmuneeSCB2324 E-mail: akmunee!"mail.comElectrolysis# $%#u nu - u #uu nu #u.... uuu#u nu # I u u u #u uu I u u&inimum 'ecom(osition (otential) E' u u u uIu uuI uu u*n -+.,-Cu .+.34*n -+.,-Cu .+.34uu uuIuu Ere/ 0 1.1+ 2u Iu E' 0 Ere/.E34 .EC . Ea Erev =u uu Iu uuu u I u (reversible cell potential) uuu u uuuuu EIR = Ohmic drop IR drop uu uuuuuuIu (uuuu uuu Iuuuuuu ) EC = u uuuIuIu (concentration polarization potential) uu uuuIuIu nI uI uuuIuIuI nI uuIuIuuuQ (bulk solution) u uI uu Ea = u uuuu (activation overpotential) uu IuuuI u uI uuu uuu u Iu Ea((lie' 0 Ere/ .E34 .EC . EaEa u u u I u 2 I u u II set up Iuuuu u l.u II C uu2.u uuu3. = E u l E u 25afel6s e7uation:0a.8 lo" 9 i 9 | i | uIuIuuuuuI (uuuu) uu u A/cm2, a b uuu uuI uu (a) uIu uuuI : u I uI uuuuu zFE (b) uu (u) u uuu I uI uuuIu (c) u uu I uuu u () uuuI u uuu G# u FE unu I u u IuArrhenius:k = A e-Ea/RT; k = rate constant uuuIuu uuIuuuu uu uu (b)io = C e-G#/RT u (c) u u i ( nuu) i = C e-(G# - FE/RT)= C e-G#/RT .e FE/RT= ioeFE/RTIu u i= Ae u take log u Tafel 0a.8 lo" 9 i 9 overpotential I uuuI uuu u uuuuu I-II overpotentialuunuuuu uI uu uI unnuu energy emciency u n :-uI , uuIIInI u 0 u : uuI I overpotentialHydrogen overvoltage on Hg electrode uIuuu u uuuuI u u 0 u u NHE uuI (Hg) u uuuu(-2 V) u 0 u -2V u u u u I uu L u uuuuu H+uuI uu u Hydrogen overvoltage u u u uuu uuuIu I H+ u Pb2+;ea' aci' 8atteryI uuuu (polarized electrode) uuu nuI I uu uuu nuunuI I uQuuu uI uu u u u (nonpolarized electrode) uu uu uu unuI I - uI uu Saturated calomel electrode (SCE) uuLu u uuuu nuuuuu (coulometry)

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