chemistry 12 name: electrochemistry practice test date
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Chemistry12
ElectrochemistryPracticeTestName:Date:Block:
I. MultipleChoice______1.Whenanelectrodelosesmass,italso:
A. loseselectrons B. actsasanoxidizingagentC. becomesreducedD. decreasesinoxidationnumber
______2.Atstandardconditions,Fe+2reactsspontaneouslywith
A. I2B. Br-C. CoD. Ag+
3.Explainyouranswertothequestionabove:______4.Whichofthefollowinghalf-reactionsisbalanced?
A. SO4-2+H2OàSO3-2+2H++2e-B. SO4-2+H2O+2e-àSO3-2+2H+ C. SO4-2+2H++2e-àSO3-2+H2OD. SO4-2+2H+àSO3-2+H2O+2e-
______5.Duringaredoxreaction,theoxidizingagent:
A. reducesotherspecies B. increasesinoxidationnumberC. gainselectrons D. becomesoxidized
______6.Foragivenredoxrxn,theoxidation#oftinchangedfrom+2to+4.Asaresult,tin:
A. lost2electronsandwasreducedB. gained2electronsandwasreduced C. lost2electronsandwasoxidizedD. gained2electronsandwasoxidized
______7.Inwhichofthefollowingcompoundsdoescarbonhaveanoxidationnumberof-2?
A. COB. CH2OC. CO2D. CH3OH
______8.Whichofthefollowingequationsrepresentsaredoxreaction?
A. ZnCl2àZn2++2Cl-B. Zn+Br2àZnBr2C. H2CO3àH2O+CO2D. 2NaI+Pb(NO3)2àPbI2+NaNO3
______9.Considerthefollowingreaction: SO4-2+8I-+8H+àS-2+2I2+4H2OThereducingagentis
A. I- B. SinSO42-C. H+ D. OinSO42-
______10.WhenMnO4-2undergoesoxidation,itmayform:
A. MnO B. MnO3C. MnO4- D. Mn2O3
11.Explainyouranswertothequestionabove:______12.Considerthefollowingreaction:
3I2+3H2Oà6H++5I-+IO3-Inthisreaction,theI2atomsundergo:
A. oxidationonly B. bothoxidationandreductionC. reductiononly D. neitheroxidationnorreduction
______13.Inanelectrochemicalcell,electronsflowfromthe
A. anodetothecathodethroughthesaltbridge B. anodetocathodethroughtheexternalcircuitC. cathodetotheanodethroughthesaltbridge D. cathodetoanodethroughtheexternalcircuit
14.Explainyouranswertothequestionabove:______15.Whenmoltenaluminumoxideiselectrolyzed,thecathodereactionis:
A. AlàAl3++3e-B. Al3++3e-àAlC. O2+4eà2O2-D. 2O2-àO2+4e-
______16.Goldisfoundinnatureinitspureformbecause:
A. Au3+isastrongreducingagent B. Au3+astrongoxidizingagentC. AuisastrongreducingagentD. Auisastrongoxidizingagent
17.Explainyouranswertothequestionabove:______18.TheelectrolysisofNa2SO4(aq)wouldproducethisgasattheanode.
A. OxygenB. HydrogenC. WatervapourD. Sulfurdioxide
Usethefollowingcelldiagramforquestions19and20.
________19.Intheaboveelectrochemicalcell,A.themassoftheanodeincreasesandthemassofthecathodeincreases.B.themassoftheanodedecreasesandthemassofthecathodedecreases.C.themassoftheanodedecreasesandthemassofthecathodeincreases.D.themassoftheanodeincreasesandthemassofthecathodedecreases.
________20.Intheaboveelectrochemicalcell,A. TheanodeisZnandthecathodeisCuB. TheanodeisCuandthecathodeisZnC. TheanodeisZn2+andthecathodeisCu2+D. TheanodeisCu2+andthecathodeisZn2+
________21.Intheoperatingelectrochemicalcellabove,thevoltageproducedis:
A.-1.10V C.0.00VB.-0.42V D.+1.10V
22.Explainyouranswertothequestionabove:
II.Problems1)Foreachofthefollowingcompounds,identifytheoxidationnumberoftheatom(s)indicated.a)Mg2TiO4 Mg= Ti= O=
b)K2Cr2O7 K= Cr= O=
c)MnO4- Mn= O=
2)AMn/Mn2+andAg+/Agelectrochemicalcellissetupatstandardconditions.Drawtheelectrochemicalcellforthisparticularreaction.Labelallpartsofthecell,includingthevoltageproduced.
3)Balancethefollowingredoxreactions.
a) Mn+2+BiO3-àMnO4-+Bi+3(acidic)
a) Sb2S3+NO3-àNO2+SO42-+Sb2O5(basic)
4)Youhavebeengiventhefollowingfivehalf-reactions:A2++2e-àAB2++2e-àBC2++2e-àCD2++2e-àDE2++2e-àE
• B2+reactedwithA.• E2+didnotreactwithC.• D2+onlyreactedwithBandA.Giventheaboveinformation,createanSRPtable:
5)Foreachofthefollowing,drawtheelectrolyticcell,includingthehalf-reactionsoccurringwithinit:
a) PlatinumelectrodesinmoltenMgBr2
b) CopperelectrodesinNaCl(aq)
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