10年試題november問(wèn)答題

In1814,SirHumphreyDavyandMichaelFaradaycollectedsamplesofaflammablegas,A,fromthegroundnearFlorenceinItaly.TheyanalysedAwhichtheyfoundtobeahydrocarbon.FurtherexperimentswerethencarriedouttodeterminethemolecularformulaofA.Whatismeantbythetermmolecular DavyandFaradaydeducedtheformulaofAbyexplodingitwithanexcessofoxygenandanalysingtheproductsofcombustion.CompleteandbalancethefollowingequationforthecompletecombustionofahydrocarbonwiththeformulaCxHy.4CxHy+(x+y)O2.............................+ 4 When10cm3ofAwasmixedatroomtemperaturewith50cm3ofoxygen(anexcess)andexploded,40cm3ofgasremainedaftercoolingtheapparatustoroomtemperatureandWhenthis40cm3ofgaswasshakenwithanexcessofaqueouspotassiumhydroxide,KOH,30cm3ofgasstillremained.Whatistheidentityofthe30cm3ofgasthatremainedattheendofthe ThecombustionofAproducedagasthatreactedwiththeKOH(aq).Whatistheidentityofthisgas?Whatvolumeofthegasyouhaveidentifiedin(ii)wasproducedbythecombustion Whatvolumeofoxygenwasusedupinthecombustionof cm3 Useyourequationin(b)andyourresultsfrom(c)(iii)and(c)(iv)tocalculatethemolecularformulaofA.Showallofyour[Total:反應(yīng)，然后檢測(cè)生成物的量來(lái)判斷原物質(zhì)的構(gòu)成。題中給出的是一種碳?xì)浠衔铮╤ydrocabon theactualnumberofatomsofeachelementpresent(1)inonemoleculeofacompound(1) yCХHУ+(x+)O2xCO24

2

yH2O(1)210cm320cm3(1) yCХHУ (x4

xCO2

210cm3 20cm3 1molofCxHygives1molofCO2whencex=1(1)1molofCxHyreactswith2molofy (xandy=4

4molecularformulaisCH4(1)[Total: Nitrogenmakesupabout79%oftheEarth’satmosphere.Asaconstituentelementofproteins,itispresentinlivingorganisms.AtmosphericnitrogenisusedintheHaberprocessforthemanufactureofWriteanequationfortheformationofammoniaintheHaber TheHaberprocessisusuallycarriedoutatahighpressureofbetween60and200atmospheres(between60×105Paand200×105Pa).StatetwofurtherimportantoperatingconditionsthatareusedintheHaberprocess.eachofyourconditions,explainwhyitisused.condition2....................................................................... Stateonelarge-scaleuseforammonia,otherthanintheproductionofnitrogenous Theuncontrolleduseofnitrogenousfertiliserscancauseenvironmentaldamagetolakesandstreams.Thisisknownas‘eutrophication’.Whataretheprocessesthatoccurwhenexcessiveamountsofnitrogenousfertilisersgetintolakesandstreams? Inmanycountries,newcarshavetocomplywithregulationswhichareintendedtoreducethepollutantscomingfromtheirinternalcombustionengines.Twopollutantsthatmaybeformedinaninternalcombustionenginearecarbonmonoxide,CO,andnitrogenmonoxide,NO.(i)Outlinehoweachofthesepollutantsmaybeformedinaninternalcombustionengine.NO(ii)Statethemainhazardassociatedwitheachofthesepollutants.CO.................................................................... PollutantssuchasCOandNOareremovedfromtheexhaustgasesofinternalcombustionenginesbycatalyticconverterswhichareplacedintheexhaustsystemofacar.(i)Whatmetalismostcommonlyusedasthecatalystinacatalytic(ii)ConstructonebalancedequationforthereactioninwhichbothCOandNOareremovedfromtheexhaustgasesbyacatalyticconverter. [Total:本題考察Haberprocess相關(guān)的內(nèi)容。工業(yè)合成ammonia是利用N2和H2在催化劑，高溫高r（explosive龍（nylon）等。另外本題還考察了內(nèi)燃機(jī)（internalcombustionengine）的污染問(wèn)題，N2+3H22NH3(1)[1]temperaturebetween300and550oCcorrectexplanationofeffectoftemperatureonrateofformationofNH3oronpositionofequilibrium(1)catalystofironorironoxidetospeedupreactionortoreduceEa(1)manufactureofHNO3ornylonorasacleaningorasarefrigerant(1)fertiliserinriverscausesexcessivegrowthofaquaticplants/algae(1)whenplantsandalgaedieO2isusedup/fishoraquaticlifedie(1)CObyincompletecombustionofthehydrocarbonfuel(1)NObyreactionbetweenN2andO2intheengine(1)COtoxic/effectonhaemoglobin(1)NOtoxic/formationofacidrain(1)[4]platinum/Pt–allowpalladium/Pdorrhodium/Rh2CO+2NO→2CO2+N2(1)[Total: Crudeoilisanaturallyoccurringflammableliquidwhichconsistsofacomplexmixtureofhydrocarbons.InordertoseparatethehydrocarbonsthecrudeoilissubjectedtofractionalExplainwhatismeantbythefollowinghydrocarbonfractionaldistillation Undecane,C11H24,isalongchainhydrocarbonwhichispresentincrudeoil.Suchlongchainhydrocarbonsare‘cracked’toproducealkanesandalkeneswhichhavesmallerGivetheconditionsfortwodifferentprocessesbywhichlongchainmoleculesmaybeprocess1process2 Undecane,C11H24,canbecrackedtoformpentane,C5H12,andanalkene.Constructabalancedequationforthisreaction. (i)Drawthethreestructuralisomersof(ii)Thethreeisomersofpentanehavedifferentboilingpoints.Whichofyourisomershasthehighestboilingpoint?isomer.........Suggestanexplanationforyour Theunsaturatedhydrocarbon,E,isobtainedbycrackinghexaneandisimportantinthechemicalindustry.ThestandardenthalpychangeofcombustionofEis–2059kJDefinethetermstandardenthalpychangeof When0.47gofEwascompletelyburntinair,theheatproducedraisedthetemperatureof200gofwaterby27.5°C.Assumenoheatlossesoccurredduringthisexperiment.(i)UserelevantdatafromtheDataBooklettocalculatetheamountofheatreleasedinthis(ii)Usethedataaboveandyouranswerto(i)tocalculatetherelativemolecularmass,Mr,ofE.Deducethemolecularformulaof[Total:要求會(huì)利用intermolecularforces解釋熔沸點(diǎn)的高低。解釋碳?xì)浠衔铮╤ydrocarbon）和分餾（fractionaldistillation）的含義。Hydrocarbon即分子中只含有hydrogen和carbon的化合物（compound）。Fractionaldistillation是根據(jù)crudeoil中不同組分的沸點(diǎn)的不同而進(jìn)行分級(jí)蒸餾的方法。acompoundwhichcontainsonlycarbonandhydrogenseparationofcompoundsbytheirboilingpoints(1)hightemperatureandhighpressure(1)hightemperatureandcatalyst(1) C11H24→C5H12+C6H12orC11H24→C5H12+2C3H6orC11H24→C5H12+3C2H4(1)[3] Pentane具有三個(gè)isomer，都是structuralisomer。判斷alkane的isomer就從最長(zhǎng)的直鏈（simplemolecule）的沸點(diǎn)由intermolecularforces決定。在pentane中只存在瞬時(shí)誘導(dǎo)力（instantaneousinduceddipole-induceddipoleforce或者Londonforce或者dispersion多Londonforce越強(qiáng)，shape越接近直線(xiàn)（即接觸點(diǎn)越多）Londonforce越強(qiáng)。本題中多，所以其Londonforce較強(qiáng)，其沸點(diǎn)也高。(ii)thestraightchainisomer(isomerBabove)(1)ithasthegreatestvanderWaals’forces(1)becauseunbranchedmoleculeshavegreaterareaofcontact/canpackmorecloselytogether(1)[6]考察標(biāo)準(zhǔn)燃燒焓（standardenthalpychangeofcombustion）的意義。Standardenthalpychangeofcombustion即1mol某物質(zhì)在標(biāo)況（standardconditions）下完全燃燒時(shí)的enthalpychange。enthalpychangewhen1molofasubstanceisburntinanexcessofoxygen/airunderstandardconditionsoriscompletelycombustedunderstandardconditions(1)heatreleased=mcδT=200x4.18x27.5=22990J=23.0kJ23.0kJproducedfrom0.47gof2059kJproduced=42.08gofE

gofEallowecfin(i)or(ii)oncandidate’sexpressionsC3H6=42EisC3H6forecf,EmustbeunsaturatedandbenolargerthanC5(1) Halogenoalkaneshavemanychemicaluses,particularlyasintermediatesinorganic Foreachreaction,statethereagentandsolventused.solventreaction2reagentsolventreaction3reagent When1-iodobutane,CH3CH2CH2CH2I,isreactedunderthesameconditionsasthoseusedinreaction1,butan-1-olisformed.Whatdifference,ifany,wouldtherebeintherateofthisreactioncomparedtothereactionof1-bromobutane?UseappropriatedatafromtheDataBooklettoexplainyour Dichlorodifluoromethane,CCl2F2,isanexampleofachlorofluorocarbon(CFC)thatwasformerlyusedasanaerosolpropellant.InSeptember2007,attheMontrealsummit,approximately200countriesagreedtophaseouttheuseofCFCsby2020.StatetwopropertiesofCFCsthatmadethemsuitableasaerosol1. WhenCFCsarepresentintheupperatmosphere,homolyticfissiontakesplaceinthepresenceofultravioletlight.WhatismeantbythetermhomolyticSuggestanequationforthehomolyticfissionof ThemostcommonreplacementsforCFCsasaerosolpropellantsarehydrocarbonssuchaspropaneandbutane.Suggestonedisadvantageofthesecompoundsasaerosol [Total:導(dǎo)致分開(kāi)carbon和halogen所需要的能量不同。C-Ibondenergy是240kJmol-1，C-Brbondenergy是280kJmol-1，所以要分開(kāi)C-Br所需的能量較高，故反應(yīng)速率較慢。withCH3CH2CH2CH2Iratewouldbefaster(1)C-IbondisweakerthanC-BrbondC-Ibondenergyis240kJmol-1,C-Brbondenergyis280kJmol-1datamustbequotedforthismark(1)[3]漏的Freon上升到平流層時(shí)會(huì)在紫外線(xiàn)的作用下釋放Cl自由基（freeredical），從而不 volatile/lowbp 而形成兩個(gè)中性的片段/freeredical。CCl2F2通常會(huì)釋放出Cl freeredical。when