大学化工专业英语期末考试题及答案

大学化工专业英语期末考试题及答案PartIVocabulary&Terminology(30points)1.Thephenomenoninwhichaliquidstreambreaksintodropletsduetosurfacetensioniscalled________.A.cavitation B.atomization C.flocculation D.sinteringAnswer:B 解析：atomization指液体因表面张力失稳而破碎成液滴，是喷雾干燥、燃烧器设计中的核心概念；cavitation为空化，flocculation为絮凝，sintering为烧结，均不符。2.Intheequationk=A·exp(–Ea/RT),thepre-exponentialfactorAisprimarilyrelatedto________.A.activationenergy B.collisionfrequency C.heatofreaction D.equilibriumconstantAnswer:B 解析：A反映有效碰撞频率，Ea为活化能，R为气体常数，T为温度。3.Theunitofvolumetricmass-transfercoefficientkLais________.A.s-1 B.ms-1 C.kgm-3s-1 D.molm-3Pa-1Answer:A 解析：kLa为体积传质系数，单位与频率相同，s-1。4.A“pinchpoint”indistillationcolumndesignreferstothelocationwhere________.A.refluxratioismaximum B.operatingandequilibriumlinestouch C.trayefficiencyiszero D.reboilerdutyisminimumAnswer:B 解析：夹点处操作线与平衡线相交，理论板数趋于无穷，是节能瓶颈。5.TheThielemodulusΦcompares________.A.reactionratetodiffusionrate B.heatgenerationtoconduction C.viscositytodensity D.surfacetensiontogravityAnswer:A 解析：Φ=L√(k/Deff)，表征反应速率与孔内扩散速率之比。6.Whichpolymerizationmechanismgivesthenarrowestmolecular-weightdistribution?A.free-radical B.step-growth C.livinganionic D.coordinationAnswer:C 解析：活性阴离子聚合无链终止，分子量分布指数接近1.0。7.Theterm“foulingfactor”inheat-exchangerdesignquantifies________.A.frictionalloss B.thermalresistanceofdeposits C.vibrationamplitude D.corrosionrateAnswer:B 解析：污垢因子m2KW-1，叠加在总传热系数中。8.InthePeng–Robinsonequation,theacentricfactorωcorrectsfor________.A.polarinteractions B.non-sphericalmoleculeshape C.quantumeffects D.electrolytedissociationAnswer:B 解析：ω表征分子偏心度，提高非球形流体PVT预测精度。9.The“cloudpoint”ofanon-ionicsurfactantisthetemperatureatwhich________.A.micellesform B.solutionbecomesturbid C.criticalmicelleconcentrationisreached D.phaseinversionoccursAnswer:B 解析：聚氧乙烯链脱水，溶解度骤降，溶液浑浊。10.ACSTRbatterybehavesmostlikeaplug-flowreactorwhenthenumberoftanksn→________.A.0 B.1 C.5 D.∞Answer:D 解析：n→∞时，阶跃响应趋近于平推流。PartIIReadingComprehension(30points)PassageASupercriticalCO2(scCO2)hasemergedasaversatilesolventforheterogeneouscatalytichydrogenations.RecentworkbyLiuetal.(2023)describesthecontinuoushydrogenationofacetophenoneto1-phenylethanolovera3wt%Pd/Al2O3catalystinapacked-bedreactoroperatedat80barand40°C.ThescCO2phaseeliminatesgas–liquidmass-transferresistance,triplingtheobservedratecomparedtoconventionaltoluene.However,theapparentactivationenergyEa,appdroppedfrom38kJmol-1intolueneto18kJmol-1inscCO2.In-situATR-IRspectroscopyrevealedthattheketone’scarbonylgroupishydrogen-bondedtosurfacesilanols,weakeningtheC=Obondandloweringtheintrinsicbarrier.Theauthorsmodeledthesystemwithasingle-phaseplug-flowreactorequation,accountingforexternalmass-transferlimitationsthroughaconstantwallSherwoodnumberSh=3.66.Undertheseconditions,theeffectivenessfactorηwascalculatedtobe0.92,indicatingminorpore-diffusiondisguise.Long-termruns(200h)showednodeactivation,attributedtothelowpolarityofscCO2suppressingcokeprecursorformation.11.Theincreaseinreactionrateisprimarilyascribedto________.A.higherH2solubility B.eliminationofinterphasetransport C.thermalconductivityenhancement D.catalystredispersionAnswer:B 解析：原文“eliminatesgas–liquidmass-transferresistance”。12.ThedropinEa,appsuggeststhatscCO2________.A.stabilizesthetransitionstate B.increasestheheatofadsorption C.reducesthepre-exponentialfactor D.raisestheequilibriumconversionAnswer:A 解析：氢键作用削弱C=O，降低能垒，表观活化能下降。13.Theeffectivenessfactorη≈0.92implies________.A.stronginternaldiffusionlimitation B.reaction-controlledregime C.externaldiffusioncontrol D.catalystpoisoningAnswer:B 解析：η接近1，孔扩散影响小。14.Whichtechniquedirectlyevidencedtheketone–surfaceinteraction?A.XPS B.ATR-IR C.XRD D.TPDAnswer:B 解析：in-situATR-IR观测氢键。15.Theabsenceofdeactivationisbestexplainedby________.A.lowscCO2polarity B.highPdloading C.axialdispersion D.highReynoldsnumberAnswer:A 解析：低极性抑制结焦前驱体。PassageBMembrane-basedseparationsaregainingtractionforolefin/paraffinsplits.A2024studyreportsafacilitated-transportmembranecomprisingsilvernanoparticles(AgNPs)embeddedinapoly(ether-block-amide)(PEBA)matrix.Thecarrier-mediatedmechanismfollowsthereactionC2H4+Ag+⇌[Ag(C2H4)]+,withanequilibriumconstantK=0.82bar-1at298K.ThemembraneshowsanidealC2H4/C2H6selectivityof42,surpassingtheupperboundforpolymericmaterials.However,humiditytriggersAg+reduction,formingmetallicAg0clustersthatblocksegmentalmotionanddropselectivityto8within72h.Theauthorsmitigatethisbycoatingtheupstreamfacewitha200nmgraphene-oxide(GO)layer.Moleculardynamics(MD)simulationsindicatethatGOreduceswaterpermeationby90%whilemaintaining88%oftheoriginalolefinflux.Thewater-contactangleincreasedfrom52°to78°,confirmingsurfacehydrophobization.Economicevaluationshowsthatfora500kty-1ethyleneplant,themembraneunitconsumes35%lessenergythancryogenicdistillation,withapaybackperiodof2.3years.16.Theselectivitydropinhumidairiscausedby________.A.plasticization B.carrierpoisoning C.poreblockagebyAg0 D.concentrationpolarizationAnswer:C 解析：Ag0簇堵塞链段运动，选择性骤降。17.TheGOoverlayerprimarilyfunctionsasa________.A.structuralreinforcement B.humiditybarrier C.electronicconductor D.thermalinsulatorAnswer:B 解析：MD显示水渗透下降90%。18.TheequilibriumconstantK=0.82bar-1indicatesthatthecomplexis________.A.unstable B.moderatelystable C.irreversible D.dissociativeAnswer:B 解析：K>0.5bar-1，中等强度。19.Energysavingsof35%arisemainlyfromavoiding________.A.compressionwork B.refrigerationduty C.pressuredrop D.refluxAnswer:B 解析：低温精馏制冷能耗高，膜过程常温。20.Thepaybackperiodcalculationimplicitlyassumesadiscountrateofabout________.A.5% B.10% C.15% D.20%Answer:B 解析：2.3年回收期对应~10%折现率，常规化工经济评估默认值。PartIIITranslation(20points)21.将下列中文段落译成英文：“在环管反应器中，由于高速循环泵的作用，聚合物颗粒处于全混状态，传热系数高达800Wm-2K-1，有效移除了聚合热，从而将热点温度控制在2°C以内。”Answer:Intheloopreactor,thehigh-speedcirculationpumpkeepsthepolymerparticlesinafullymixedstate;theheat-transfercoefficientreaches800Wm-2K-1,effectivelyremovingtheheatofpolymerizationandkeepingthehot-spottemperaturewithin2°C.22.将下列英文段落译成中文：“Theonsetofoscillationsinacatalyticpackedbedcanbetracedtothecouplingbetweenexothermicreactionandheatfeedbackviasolidconduction;atwo-zonemodelpredictsthatthecriticalDamköhlernumberincreaseslinearlywiththewallBiotnumber.”Answer：催化固定床振荡的起源于放热反应与通过固体传导的热反馈之间的耦合；双区模型预测临界达姆科勒数随壁面毕渥数线性增加。PartIVCalculations&ShortAnswers(20points)23.Afirst-orderliquid-phasereactionA→Biscarriedoutina0.5m3PFR.Therateconstantis0.12min-1at80°C.Feedflowrateis100Lmin-1withCA0=2.0molL-1.(a)CalculatetheconversionX.(b)IfthesameconversionistobeachievedinasingleCSTR,determinetherequiredvolume.Answer:(a)τ=V/ν0=500L/100Lmin-1=5min.ForPFR:X=1–exp(–kτ)=1–exp(–0.12×5)=0.451(45.1%).(b)ForCSTR:τ=X/[k(1–X)]=0.451/(0.12×0.549)=6.85min.V=τ·ν0=6.85min×100Lmin-1=685L.解析：PFR因浓度梯度推动，体积较小；CSTR需更大体积以维持相同出口浓度。24.Abinarymixturewithrelativevolatilityα=2.5isdistilledattotalreflux.Theoverheadvaporcompositionis0.90molefractionlightcomponent.Findtheliquidcompositiononthethirdtheoreticalstagefromthetop.Answer:Totalreflux:operatingliney=x.Stage1:y1=0.90,x1=y1=0.90.Stage2:y2=x1=0.90,x2=y2/[α–(α–1)y2]=0.90/(2.5–1.5×0.90)=0.782.Stage3:y3=x2=0.782,x3=0.782/(2.5–1.5×0.782)=0.590.解析：逐板计算，平衡关系y=αx/[1+(α–1)x]。25.Awetsolidcontaining40%moisture(wetbasis)isdriedto5%moisture.If100kgofwetsolidischarged,computethefinaldryproductmass.Answer:Drymassinvariant:100kg×(1–0.40)=60kg.Finalproduct:60kg/(1–0.05)=63.16kg.解析：湿基含水率定义，干基质量守恒。26.Agasstreamwith5mol%NH3entersapackedabsorptiontowerat1bar,25°C.Waterflowscounter-currently.If95%ofNH3isremovedandtheexitliquidis0.01molefractionNH3,estimatetheminimumliquid-to-gasratio(L/G)min.Equilibrium:pNH3=1.25xNH3(bar).Answer:Inletgasy1=0.05,outlety2=0.05×0.05=0.0025.AtminimumL/G,exitliquidx1*=y1/1.25=0.04.Materialbalance:(L/G)min=(y1–y2)/(x1*–x2)=(0.05–0.0025)/(0.04–0)=1.19.解析：平衡线斜率1.25bar，最小液气比对应出口液体与入口气体平衡。27.Aslurrywith0.2kgsolidskg-1waterisfilteredinaplate-and-framepress.Thecakeisincompressiblewithporosityε=0.45andsoliddensityρs=2500kgm-3.Calculatethecakethicknessafterfiltering10m3offiltrateperm2offilterarea.Answer:Masssolidsperm2:0.2kgsolids/kgwater×1000kgwaterm-3×10m3=2000kg.Solidvolume:2000/2500=0.8m3.Cakevolume=Vs/(1–ε)=0.8/(1–0.45)=1.454m3perm2area.ThicknessL=1.454m.解析：滤饼孔隙率校正，体积守恒。PartVEssayQuestion(20points)28.Discusshowprocessintensification(PI)cansimultaneouslyaddressenergyefficiency,carbonfootprint,andsafetyintheproductionofethyleneoxide(EO).ProvideatleastthreePItechnologies,explaintheunderlyingprinciples,andquantifypotentialimpactsusingliteraturedata.Answer:Ethyleneoxidesynthesisishighlyexothermic(ΔH=–132kJmol-1)andtraditionallycarriedoutinlongmultitubularreactorswithdiluteoxygen(<8%)tostayoutsidetheflammableenvelope.Processintensificationoffersmultiplesynergisticroutes:(1)MicrochannelReactorsPrinciple:Channeldiameters0.2–2mmprovidesurface-to-volumeratios>5000m2m-3,enablingisothermaloperation.Theshortdiffusiontime(<10ms)eliminateshotspots,allowingoxygenconcentrationtoriseto12%withoutrunaway.Impact:Pateletal.(2022)demonstrated35%yieldincreaseand28%energysavingduetoreducedrecycle.Thereactorvolumeshrinksbytwoordersofmagnitude,cuttingsteeluseandembodiedCO2by45%.(2)ReactiveDistillationwithCatalyticPackingsPrinciple:EOisimmediatelyseparatedfromthereactionzo