C

Camachocell67●CCCadmiumcellWestonnormalelementCadmiumtelluride—AII–IVcompoundsemicon-ductorfrequentlyemployedininfraredsystems(activecomponentininfrareddetectors)andphotovoltaicde-vices.Electrochemicalpassivationhasbeenemployedtoimprovesurfacerecombinationbehavior.Refs.:[i]WeiC,MishraKK,RajeshwarK()ChemMater:;[ii]LemassonP()JPhysD:ApplPhys:;[iii]ForniF,Inno-centiM,PezzatiniG,ForestiML()ElectrochimActa:RHCalibration—Asetofoperationsthatestablishes,un-derspecifiedconditions,asuitablerelationshipbetweenvaluesofquantitiesindicatedbythemeasuringsystem,andthecorrespondingvaluesrealizedbystandards[i].Themeasuringsystemcaninvolveasimplevolumetricflask[ii]orsophisticatedinstrumentaltechniques[iii].Mostinstrumentalmethodsofanalysisarerelativesincetheyregisterasignalduetosomephysicalpropertyoftheanalyte.Spectrometers,forexample,measurethefractionofelectromagneticradiationthatisabsorbedfromalightsourcebythesample.Thisfractionmustberelatedtotheanalyteconcentrationbyitscomparisonagainstthefractionoflightabsorbedbyaknowncon-centrationoftheanalyte.Refs.:[i]McNaughtAD,WilkinsonA()IUPACcompendiumofchemicalterminology,ndedn.BlackwellScienctificPublications,Ox-ford;[ii]DayRA,UnderwoodAL()Quantitativeanalysis.PrenticeHall,NewJersey;[iii]WillardHH,MerrittLL,DeanJA,SettleFA()Instrumentalmethodsofanalysis.Wadsworth,CaliforniaFGCallancell—ThiswasaGrovebatterywhereapla-tinizedleadelectrodewasusedinsteadoftheplatinizedplatinumelectrode.Ref.:[i]HauckWP()DieGalvanischenBatterien,AccumulatorenundThermosäulen,ndedn.Hartleben’sVerlag,WienFSCallaudcell—ThiswasavariantoftheDaniellcell.Seealsozinc,Zn+/Znelectrodes,Zn+/Zn(Hg)electrodes,zinc–airbatteries(cell),andLeclanchécell.Ref.:[i]HauckWP()DieGalvanischenBatterien,AccumulatorenundThermosäulen,ndedn.Hartleben’sVerlag,WienFSCalomelelectrode—isanelectrodeofthesecondkind.ItwasintroducedinbyOstwald,F.W.Asaref-erenceelectrodeoffixed,well-known,andveryrepro-duciblepotential,itisstillacommonlyusedreferenceelectrodeinelectrochemistry[i–iii].Itconsistsofmer-cury,sparinglysolublemercurouschloride(calomel),andachloride-containingsolution.Theelectrodenetre-actioncanbeformulatedinthefollowingway:HgCl(s)+e−Hg(l)+Cl−(aq).Thepotentialoftheelectrodeagainstthestandardhy-drogenelectrodeisgivenbytheequation:E=Ec(HgCl,Hg)−RTFlnaCl−,whereEc(HgCl,Hg)istheformalpotentialofthecalomelelectrode(.VatC)takingintoac-countthestandardpotentialE(Hg/Hg+)andthesolubilityproductofcalomel,KHgClaccordingtoEc(HgCl,Hg)=E(Hg/Hg+)+RTFlnKHgCl,Risthegasconstant,Tistheabsolutetemperature,FistheFara-dayconstant,andaCl−istheactivityofthechlorideions.Commonly,saturatedpotassiumchloridesolutionisused,however,sodiumchlorideisadvisabletoapplywhenworkingwithperchlorate-containingmedia.Prin-ciples,preparation,andpotentialsatdifferenttempera-tureshavebeengiveninmonographs.AtCtheexperimentallydeterminedpotentialoftheKCl-saturatedcalomelelectrode(SCE)is.Vvsstandardhydrogenelectrode(SHE)whentheliq-uidjunctionpotentialbetweentheKClsaturatedsolu-tionandabuffersolutionistakenintoaccount[i].With-outtheliquidjunctionpotentialthatvalueis.Vvs.SHE[i].Refs.:[i]IvesDJG,JanzGJ()Referenceelectrodes,theoryandprac-tice.AcademicPress,NewYork;[ii]ZhangXN()Referenceelec-trodes.In:YuTR,JiGL(eds)Electrochemicalmethodsinsoilandwaterresearch.PergamonPress,Oxford,pp–;[iii]KahlertH()Ref-erenceelectrodes.In:ScholzF(ed)Electroanalyticalmethods.Springer,Berlin,pp–HKCamachocell—Thiswasachromicacidbatterywithzincanodes,andaconstructionthatthechromicacidsolutionsflowedthroughthecathodecompartmenthousingtheinertcarbonelectrodes.SeealsoDaniellcell,zinc,Zn+/Znelectrodes,Zn+/Zn(Hg)elec-trodes,zinc–airbatteries(cell),andLeclanchécell.Ref.:[i]HauckWP()DieGalvanischenBatterien,AccumulatorenundThermosäulen,ndedn.Hartleben’sVerlag,WienFS68Candidocell●CCandidocell—ThiswasavariantoftheDaniellcell.Seealsozinc,Zn+/Znelectrodes,Zn+/Zn(Hg)electrodes,zinc–airbatteries(cell),andLeclanchécell.Ref.:[i]HauckWP()DieGalvanischenBatterien,AccumulatorenundThermosäulen,ndedn.Hartleben’sVerlag,WienFSCapacitance—Symbol:C,unit:faradF(CV−=AsV−,inSIbaseunitsm−kg−sA).MeasureofthecapabilityofacapacitortostoreelectricalchargeatapotentialdifferenceΔU(voltage)betweenthetwoplatesofthedevice:C=QΔU.RHCapacitance,stray—istheundesiredandunintentionalcapacitancepartsofanexperimentalsetuporinstru-ment,as,e.g.,anelectricalconductingwireandthechas-sis.FSCapacitivecurrentchargingcurrentCapacitivedeionization—Incapacitivedeionization,waterflowsbetweenparallelpairsofporouscarbonelectrodes(suchascarbonaerogelelectrodes)thataremaintainedatapotentialdifferencegreaterthan.V.Ions(andotherchargedparticlessuchascolloidsandmicroorganisms)becomeelectrostaticallyimmobilizedonthechargedsurfaces,thusallowingpurewatertopassthrough.Whentheelectrodesarefullycoated,theyareregeneratedsimplybyremovingthepotentialdifference,thusallowingthechargedimpuritiestoflowaw