雨课堂学堂在线学堂云Organic Spectroscopic Analysis(中南民族大学)单元测试考核答案

第1题Whichofthefollowingformulaeisconsistentwithamolecularionofm/z73inamassspectrometryexperiment?()AC3H8N2BC4H11NCC4H10ODC3H5NO第2题Whichofthefollowingstatementsregardingmassspectrometryisfalse?()AThebasepeakofasimpleketoneisusuallyattributabletoanacyliumion.BThemolecularionofcarbonylcompoundswitha-C-Hreadilyundergoeseliminationofanalkenetogivearelativelystableenolradicalcation.CThemolecularionpeakofsomealcoholsisveryweakbecauseitreadilylosesanalkylradicaltogivearelativelystableoxonium(hydroxycarbenium)ion.DStructurallyisomericalkanescannotbedistinguishedbylowresolutionmassspectrometry.第3题Whichofthefollowingstatementsregardingelectron-impactmassspectrometryistrue?()ASamplesneedisotopiclabels.BThebasepeakisformedbylossofoneelectronfromeachvaporisedmoleculebyanelectronbeam.CCompoundsmusthaveafunctionalgrouptoshowamassspectrum.DAmeaningfulmassspectrumcansometimesbeobtainedonaverysmallsampleofanimpurecompound.第4题Whichofthefollowingstatementsiswrong?()AAconventionalmassspectrometeremployshighenergyUVradiation.BAconventionalmassspectrometerdoesnotemployaspectrophotometricdetector.CConventionalmassspectrometrydoesnotalwaysrequiresamplesofhighpurity.DAmassspectrumdoesnotshowsignalsduetounchargedradicals.第5题Whichofthefollowingstatementsregardingmassspectrometryiswrong?()AInanormalmassspectrometer,electronimpactcausesamoleculetoloseanelectronandbecomeamolecularradicalcationwhichdecomposesintofragmentcationsandradicals.BOnlycationscanbedetectedbyanormalmassspectrometer.CAcompoundwhosemoleculescontainjustonebromineatomshowstwomolecularionpeaksofsimilarintensity,oneat+1andoneat-1oftheaveragem/zvalue.DMolecularionpeaksalwayshaveeven-numberedvaluesofm/z.第6题Whichofthefollowingstatementsiswrong?()AUVabsorptionisattributabletoelectronictransitions.BUVspectraprovideinformationaboutvalenceelectrons.CIRabsorptionisattributabletotransitionsbetweenrotationalenergylevelsofwholemolecules.DNMRspectrometersuseradiofrequencyelectromagneticradiation.第7题Massspectrometrydiffersfromspectroscopybecause()Aitisadestructivetechnique.Bitisanondestructivetechnique.Citinvolvestheabsorptionofradiowaves.Ditinvolvestheabsorptionofinfraredwaves.Eitinvolvestheabsorptionofultravioletwaves.第8题Whichofthefollowingtechniqueswouldbemostusefultoidentifyandquantifythepresenceofaknownimpurityinadrugsubstance?()ANMRBMSCIRDHPLC第9题Massspectrometricsignalsofimpuritiesdonotnormallyobscurethesignificantpeaksofthemaincompound.第10题Amassspectrumrecordsrelativeabundancesofthemolecularcationanditsfragmentcationsbytheirmass-to-chargeratios,

m/z.Thebasepeakcorrespondstothemostabundantionwhichisnotusuallythemolecularion.第1题Whichhydrogenof1-chloropent-2-eneshowsthelargestchemical(downfield)shiftinitsNMRspectrum?()AtheHonC1BtheHoneitherC2orC3CtheHonC4DtheHonC5第2题Whichcarbonof(A)-(D)ofhex-3-en-2-onehasthesmallest(mostupfield)chemicalshiftintheNMRspectrum?()AC1BC2CC4DC6第3题Ina31PNMRexperimentonanunknowncompound,asingleresonancewithaseptetpattern(1:6:15:20:15:6:1)isobserved.Whichofthefollowingstructureswouldbeconsistentwiththisobservation?()APF3BPH3CPMe3DPF6-第4题Howmanypeakswillbeseeninthealkeneregion(δca.5)ofthe1HNMRspectrumofthemoleculeCl-CH=CH-CO2H?()A4B2C1D3第5题InaprotonNMRexperimentwithafrequency(v)of60MHz,themagneticfieldBrequiredforresonanceis1.4T.Calculatethemagneticfieldrequiredforresonanceoftheprotoninaspectrometerwithafrequencyof500MHz.()A2.8TB11.7TC0.7TD14.0T第6题Whichoneofthefollowingnucleihasamagneticmoment(sothatanNMRexperimentcanbeperformed)?()A12CB16OC14ND32S第7题Couplingcausesthepeaksin1HNMRspectratobesplitinto()AtwopeaksBmultiplepeaksequaltothenumberofhydrogensonsurroundingatomsCmultiplepeaksequaltothenumberofsurroundingcarbonatomsDmultiplepeaksequaltothenumberofhydrogenonsurroundingatoms,plusone第8题WhatisshieldinginNMR?()AUsingacurvedpieceofmetaltoblockanopponentsattackBPuttingmetalaroundanRfsourceCWhenthemagneticmomentofanatomblocksthefullinducedmagneticfieldfromsurroundingnucleiDBlockingpartsofamoleculefromRfradiation第9题NMRspectroscopyindicatesthechemicalnatureofthe__________andspatialpositionsof________.AElectrons.ProtonsBNeutrons,electronsCNuclei,ElectronsDNuclei,neighbouringnuclei第10题NMRspectrometerprovides__________and___________methodofdeterminingstructureinsolublechemicalcompounds.AAccurate,destructiveBAccurate,non-destructiveCInaccurate,destructiveDInaccuratenon-destructiveInfraredSpectroscopy(IR)(Problems)第1题RamanandIRspectraforagivenspeciesoftenresembleoneantherquiteclosely.Thereare,however,enoughdifferencestomakethetechniquescomplementaryratherthancompetitive.第2题Whichofthefollowingstatementsiswrong?()AThewavenumberofabandinanIRspectrumisproportionaltothefrequencyoftheassociatedmolecularvibration.BWaterisagoodsolventforrecordingUVspectraofwater-solublecompounds.CWaterisagoodsolventforrecordingIRspectraofwater-solublecompounds.DHydrogenbondinginhydroxycompoundsleadstobroadeningofspectralbandsattributabletoO-Hstretchingvibrations.第3题WhichofthefollowingstatementsregardingIRspectroscopyiswrong?()AInfraredradiationishigherinenergythanUVradiation.BInfraredspectrarecordthetransmissionofIRradiation.CMolecularvibrationsareduetoperiodicmotionsofatomsinmolecules,andincludebondstretching,torsionalchanges,andbondanglechanges.DInfraredspectragiveinformationaboutbondingfeaturesandfunctionalgroupsinmolecules.第4题HowdoesIRspectroscopyidentifydifferentmolecules?()ABymeasuringthevibrationalmovementandabsorptionofeachbondBBymeasuringtheweightofeachatomCBywatchinghowthemoleculereactstodifferentcompoundsDBybreakingapartthemoleculeintoindividualatoms第5题IdentifythebondswhichwillproducestrongabsorptionsintheIRregionoftheelectromagneticspectrum.I.C-ObondII.C=CbondIII.C=Obondanswerchoices()AIandIIonlyBIandIIIonlyCIIandIIIonlyDI,IIandIII第6题AmoleculeabsorbsIRatawavenumberof1720cm-1.Whichfunctionalgroupcouldaccountforthisabsorption.()AaldehydesBalcoholsCethersDalkenes第7题WhichofthefollowingareconsideredtobethelowestformofElectromagneticradiation?()AIRradiationBMicrowavesCUVradiationDRadiowaves第8题Whichinfraredtechniquecanmeasuretwospectraatonce?()AFTIRspectroscopyBFTIR-ATRspectroscopyCDispersiveinfraredspectroscopyDFTIRmicroscopyEnone第9题Ininfraredspectroscopywhichfrequencyrangeisknownasthefingerprintregion?()A400-1400cm-1B1400-900cm-1C900-600cm-1D600-250cm-1第10题Whichofthefollowingstatementsiswrong?()AUVabsorptionisattributabletoelectronictransitions.BUVspectraprovideinformationaboutvalenceelectrons.CIRabsorptionisattributabletotransitionsbetweenrotationalenergylevelsofwholemolecules.DNMRspectrometersuseradiofrequencyelectromagneticradiation.RamanSpectroscopy(RAMAN)(Problems)第1题TheadvantageofRamanspectraoverinfraredliesinthefactthatwaterdoesnotcauseinterference,andglassorquartzcellscanbeemployed.第2题Ramanspectrayieldmoreinformationaboutcertaintypesoforganiccompounds(e.g.fullerenes,C60,carbonnanotubes)thandotheirinfraredcounterparts.第3题RamanandIRspectraforagivenspeciesoftenresembleoneantherquiteclosely.Thereare,however,enoughdifferencestomakethetechniquescomplementaryratherthancompetitive.第4题RamanSpectroscopyisusedtostudythevibrational,rotational,andotherlow-frequencymodesinasystem.第5题ForwhichofthefollowingmoleculeswouldyouexpecttheinfraredactivefundamentalstobeRamaninactiveandviceversa?()ANO2BfluorobenzeneCbenzeneDfluoroetheneUltravioletandVisible(UV-vis)Spectroscopy(Problems)第1题WhichofthefollowingareconsideredtobethelowestformofElectromagneticradiation?()AIRradiationBMicrowavesCUVradiationDRadiowaves第2题Whichofthefollowingstatementsiswrong?()AThewavenumberofabandinanIRspectrumisproportionaltothefrequencyoftheassociatedmolecularvibration.BWaterisagoodsolventforrecordingUVspectraofwater-solublecompounds.CWaterisagoodsolventforrecordingIRspectraofwater-solublecompounds.DHydrogenbondinginhydroxycompoundsleadstobroadeningofspectralbandsattributabletoO-Hstretchingvibrations.第3题AbsorptionofradiationintheUVrangeattributableton→π*electronictransitionsischaracteristicofwhichofthefollowingtypesofcompounds?()AAromatichydrocarbons.BUnsaturatedcarbonylcompounds.CNon-conjugatedpolyenes.DConjugatedpolyenes.第4题Whichofthefollowingstatementsiswrong?()AAconventionalmassspectrometeremployshighenergyUVradiation.BAconventionalmassspectrometerdoesnotemployaspectrophotometricdetector.CConventionalmassspectrometrydoesnotalwaysrequiresamplesofhighpurity.DAmassspectrumdoesnotshowsignalsduetounchargedradicals.第5题WhichofthefollowingstatementsregardingIRspectroscopyiswrong?()AInfraredradiationishigherinenergythanUVradiation.BInfraredspectrarecordthetransmissionofIRradiation.CMolecularvibrationsareduetoperiodicmotionsofatomsinmolecules,andincludebondstretching,torsionalchanges,andbondanglechanges.DInfraredspectragiveinformationaboutbondingfeaturesandfunctionalgroupsinmolecules.第6题Whichofthefollowingstatementsiswrong?()AUVabsorptionisattributabletoelectronictransitions.BUVspectraprovideinformationaboutvalenceelectrons.CIRabsorptionisattributabletotransitionsbetweenrotationalenergylevelsofwholemolecules.DNMRspectrometersuseradiofrequencyelectromagneticradiation.X-rayPhotoelectronSpectroscopy(XPS)(Problems)第1题XPSspectraareobtainedbyirradiatingasolidsurfacewithabeamofX-rayswhilesimultaneouslymeasuringthekineticenergyofelectronsthatareemittedfromthetop1-10nmofthematerialbeinganalyzed.第2题XPScanmeasuretheelementalcomposition,empiricalformula,chemicalstateandelectronicstateoftheelementswithinamaterial.第3题WhenanatomormoleculeabsorbsanX-rayphoton,anelectroncanbeejected.Thekineticenergy(KE)oftheelectrondependsuponthephotonenergy(hν)andthebindingenergy(BE)oftheelectron(i.e.,theenergyrequiredtoremovetheelectronfromthesurface).Bymeasuringthekineticenergyoftheemittedelectrons,itispossibletodeterminewhichelementsarenearamaterial’ssurface,theirchemicalstatesandthebindingenergyoftheelectron.第4题XPSisusedtolookatthesurfacecompositionandoxidationstateofspeciespresentinthetop5-10atomiclayers.第5题SurfacechargeeffectsinXPS

causeavoltagebiastobuildupandshiftthespectrastrictlytohigherbindingenergy.第6题UsingXPSspectra,itispossibletorepresentFe3+andFe2+ionofFe3O4separately.第7题XPSexaminesthecrystallinityofasample.Ittellsyouthecrystalstructure(s)ofyoursample,aswellasthespacegroup,latticeparameters,preferredorientationandcrystallitesize.第8题ConcerningthedifferencesbetweenX-rayPhotoelectronSpectroscopy(XPS)andAugerElectronSpectroscopy(AES),whichofthefollowingisnottrue?(

)AAESisasingle-stepphoto-emissionprocess,XPSisatwo-stepemissionprocess.BWe

canseeAESpeaksinXPS,butnotXPSpeaksinconventionalAES.CAESrequires

conductivesubstrateswhereasXPSdoesnotDAESismoresurfacesensitiveandhasahigherspatialresolution第9题WhichofthefollowingareasisnotsuitedtomeasurementbyXPS?(

)AElementalcompositionBlatticeparametersCChemicalstateDLayerthicknessintheupperportionofsurfaces第10题WhichelementismostoftenusedforbindingenergycorrectioninXPS?(

)ACarbonBOxygenCNitrogenDSiliconX-RayDiffraction(Problems)第1题WhichofthefollowingisnotusuallyanadvantageofsynchrotronradiationcomparedwithlaboratoryX-raysources?()AIntensity.BSpeedofdatacollection.CWavelengthselection.DFinelyfocusedX-raybeam.ECost.正确答案：E第2题ThescatteringcontributionofoneindividualatomoriontothetotalX-raydiffractionpatternofacrystalstructuredependsonallbutoneofthefollowingpropertiesoftheatom/ion.Whichisthepropertythathasnoeffect?()ATheidentityoftheelement.BTheoxidationstate.CTheisotope.DThepositionoftheatom/ionintheunitcell.EThevibrationalmotionoftheatom/ion.第3题Whichofthefollowingstatementsaboutlatticesandunitcellsiscorrect?()ALatticepointsarechosentolieonatoms.BLatticepointsallhaveidenticalsurroundings.CLatticescanbeprimitiveorcentred.DUnitcellsareconstructedbyconnectingadjacentlatticepointstogivethesmallestpossiblerepeatunit.EDifferentpossibleunitcellshapesdefinethesevencrystalsystems.FAunitcellcontains