1 Electrodes and Electrochemical Cells “Batteries”
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Transcript of 1 Electrodes and Electrochemical Cells “Batteries”
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Electrodes and Electrodes and Electrochemical CellsElectrochemical Cells
Electrodes and Electrodes and Electrochemical CellsElectrochemical Cells
““Batteries”Batteries”
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Electric power conversion in electrochemistry
Chemical Reactions
Electric Power
Electrolysis / Power consumption
Electrochemical battery / Power generation
Types of the electrochemical system for electric power generation
Primary batteries
POWER
Fuel cells
Reaction products (exhaust)
Reductant (fuel)
Oxidant
POWER
Secondary batteries
Recharge
POWER
POWER
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Types of Electrode (Summery)
EElleeccttrrooddee TTyyppee DDeessiiggnnaattiioonn
MMeettaall//mmeettaall iioonn MM((ss))||MM++((aaqq))
GGaass PPtt((ss))||XX22((gg))||XX++((aaqq)) oorr PPtt((ss))||XX22((gg))||XX--((aaqq))
MMeettaall//iinnssoolluubbllee ssaalltt
MM((ss))||MMXX((ss))||XX--((aaqq))
RReeddooxx
PPtt((ss))||MM++((aaqq)),,MM22++((aaqq))
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Types of Electrode (continued)
RReeddooxx CCoouuppllee HHaallff rreeaaccttiioonn
MM++//MM MM++((aaqq)) ++ ee-- MM((ss))
XX++//XX22
XX22//XX--XX++((aaqq)) ++ ee-- ½½ XX22((gg))½½ XX22((gg)) ++ ee-- XX--((aaqq))
MMXX//MM//XX-- MMXX((ss)) ++ ee-- MM((ss)) ++ XX--((aaqq))
MM22++//MM++ MM22++((aaqq)) ++ ee-- MM++ ((ss))
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Simple Type:Anode| electrolyte | Cathode
Complex Type:A | Anolyte || Catholyte|C
Cell Conventions
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Cells Connections
Me1n+ SO4
2- Me2n+ SO4
2-
Me2
Me20 - ne- = Me2
n+
ANODE
Me2n+ - ne- = Me2
0
CATHODE
Salt Bridge
Me1
Principles of power generation in the electrochemical systems
Me1n+ SO4
2- Me2n+ SO4
2-
Me2
Me20 - ne- = Me2
n+
ANODE
Me2n+ - ne- = Me2
0
CATHODE
Me1 Diaphragm
Membraneor
Principles of power generation in the electrochemical systems
Pt|H2(g)| HCl | AgCl(s) ,Ag(s) .
H2 2H+ +2e AgCl+eAg+Cl-
Simple Cell
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Zn
Zn2+ ions
Cu
Cu2+ ions
wire
saltbridge
electrons
Zn
Zn2+ ions
Cu
Cu2+ ions
wire
saltbridge
electrons
Zn --> ZnZn --> Zn2+2+ + 2e- + 2e- CuCu2+2+ + 2e- --> Cu + 2e- --> Cu
<--Anions<--AnionsCations-->Cations-->
OxidationOxidationAnodeAnodeOxidationOxidationAnodeAnode RedReductionuction
CatCathodehodeRedReductionuctionCatCathodehode
RED CATRED CAT
Zn|Zn 2+||Cu 2+|Cu
Complex Cell
Pt | Fe 2+ ,Fe 3+ | | Ag+ | Ag
Copyright©2000 by Houghton Mifflin Company. All rights
reserved.
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Copyright©2000 by Houghton Mifflin Company. All rights
reserved.
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Zn|ZnSO4||HCL|H2,Pt
ZnZn 2++2e
H++2e H2
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Dry Cell Battery
ZnCl2
Anode Anode Zn ---> ZnZn ---> Zn2+2+ + 2e- + 2e-
Cathode Cathode 2 NH2 NH44++ + 2e- - + 2e- -22 NH NH33 + +
HH22