IMG_0001_NEW_0027_001 - V Zf -+ Ztf* + 2; ; Eosr1 >zn?*...

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l) Galvanic Gells Stop charge build-up = complete circuit + Porous Disk or Salt Bridge 2) Measure driving force on e-s + Voltmeter : Cell Potential (E^^,,) I : erectromo,iu" ioi" ("*D -|- unit : volt (v; I Volt: I joule of work per coulomb of charge transferred (1-$.u/9 3) Cell diagram: Zn(s\lZfi*(aq, : Cathode I I M)l lcuh(aq, I M)lCu(s) t Half-cell (oxidation) Salt bridge (Porous disk) IIalf-cell (reduction) Cell Potential (Eo."n) - Zn-->7.rF +2r rc Cu2*_> Cu + 2e- E"co'*-co =0.34V Ez--n* =0-76V Standerd cell potential (E".4) : Sum of electrode potentials E" efi = E" zn-tzn" * E" c,t" -*u / \ Standardpotential Standardpotential o'/6vf o.)Qv =/.tv E"ar for oxidation for reduction Standard Electrode Potentials (f) (Half-cel I potentials) Z* =measure of how easily species is reduced or oxidised @ standard conditions (25"C, I atm, 1 M) Cu2* + 2e- -+ Al : Eog,rz*-rgu: +0.34
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Unformatted text preview: V Zf -+ Ztf* + 2; ; Eosr1 >zn?* : *0.76 V . Change direction of reaction + Change sign of .E' ,\ Cri + Cuz* + 2t ; Eo6ue6'z* : -0.34 V 2Af* + 4{ -+ 2Cu ; Eocuz+-rc,r: *0.34 V + process occurs more easr Calculating Eo ""1 {nV convention: Standard Electrode Potentials ALWAYS written and tabulated as Standard Reduction Potentials Unless otherwise specified: ,E'" = standard reduction potential Cu2* + 2e- -+ Cu : E": *0.34 V Zrf* + 2{ -+ Zn ; Eo - 4.76v E cell : EoR.d.,"tion (Cathode) f ffo"lourion (Anode) E r*ll: EoR.d.r",ioo (Cathode) - P*"do",ion (Anode) .P".p| = Eo lcethode; Righg -,F (dnodc: Left) I 'f /a( t'"-(\ Zn(s) + Cu2*(aq) -+ [email protected]) + Cu(s) t'o-ltcv - C'./6r)= /.1 Reaction is spontaneous in the direction that has a positive value for.E"cell 8 Eo""ll:...
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This note was uploaded on 12/27/2011 for the course CHEM 122 taught by Professor Williams during the Fall '10 term at Simon Fraser.

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