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Chemistry12ElectrochemistryIV
Name:Date:Block:
1. TheElectrochemicalCell2. StandardCellPotentials
TheElectrochemicalCell
• Portablesourceofelectricityinwhichelectricityisproducedbyaspontaneousredoxreactionwithinthecell
• Alsoreferredtoasa_______________cellor_______________cell.• Oxidationhalf-reactionandthereductionhalf-reactionareseparated.• Electronscanonlytravelfromthereducingagenttotheoxidizingagentwhenthetwoare
connectedthroughan______________________________.BasicComponents:
Astandardelectrochemicalcell
Electronsflowfromthe_______________tothe_______________• Cathode:
• Anode:
• SaltBridge:
StandardCellPotentials
Whenelectronsflowthroughoutasystem,avoltage,orelectricalpotentialisproduced.Thiscanbemeasuredbycomparingthedifferenceinelectricalpotentialbetweentwohalf-cells.
• Writethehalf-reactionthewayitoccursandthenaddthehalf-cellpotentialstogether.• Ahalf-cellpotentialdoesn’tchangewhenitshalfreactionismultipliedbyaninteger.
Example:
DeterminethevoltageofastandardcellconsistingofaNi|Ni2+halfcellandanI2|I-halfcell.• Writetheoxidationhalf-cellreactionanditsoxidationpotential.
• Writethereductionhalfreactionanditsreductionpotential.
• Addthereductionpotentialtotheoxidationpotential.Ifthestandardcellpotential(Eo)ispositiveforaredoxreaction,thereactionisexpectedtobespontaneous.
Drawanelectrochemicalcellfortheabovereaction:
Practice:
Determinethestandardcellpotentialofeachofthefollowingcombinationsofhalf-cells.Showtheoxidationandreductionhalf-reactionsaswellastheoverallredoxreactionoccurringineachcell.Drawtheelectrochemicalcellandthemovementofelectrons.
1. Ni|Ni2+andanSn|Sn2+
2. Cu|Cu2+andanAl|Al3+
3. Designanelectrochemicalcellforlead-plating.
CalculatetheSRPforthefollowingreactions:
a) Ag+Ni2+àAg++Ni
b) Ag++NiàAg+Ni2+
c) Sn+Al3+àAl+Sn2+
d) F2+CuàF-+Cu2+
e) F2+MgàMg2++F-
HebdenWorkbookPg.224#36-38,40,41,Pg.228#47