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