首页
试卷库
试题库
当前位置:
X题卡
>
所有题目
>
题目详情
已知函数f(x)=log2x,若在[1,4]上随机取一个实数x0,则使得f(x0)≥1成立的概率为( )
查看本题答案
包含此试题的试卷
高二上学期数学《》真题及答案
点击查看
你可能感兴趣的试题
已知函数y=log2x-2log4x-2≤x≤8.1令t=log2x求y关于t的函数关系式并写出t的
已知函数fx=log2x+1将函数y=fx的图象向左平移一个单位再将图象上所有点的纵坐标伸长到原来的
已知函数fx=x2-4x+a+3a∈R..1若函数y=fx的图象与x轴无交点求a的取值范围2若函数y
已知函数fx=x2-2x-3x∈[-14].1画出函数y=fx的图象并写出其值域2当m为何值时函数g
设fx是定义在R.上的偶函数且f2+x=f2﹣x当x∈[﹣20]时fx=x﹣1若在区间﹣26内函数y
(1,4)
(4,+∞)
(
,1)∪(4,+∞)
(0,1)∪(1,4)
已知函数fx=log44x+1+kxk∈R.为偶函数.1求k的值2若方程fx=log4a·2x-a有
已知函数fx=log44x+1+kxk∈R.是偶函数.1求k的值2设gx=log4a·2x-a若函数
已知函数fx满足fx=f2x且当x∈[12时fx=lnx.若在区间[14内函数gx=fx﹣2ax有
已知函数y=fx是定义在R.上的函数对于任意函数y=fx-1≤x≤1是奇函数又知y=fx在[01]上
已知函数fx=3-2log2xgx=log2x.1当x∈[14]时求函数hx=[fx+1]·gx的值
已知函数fx=x2的值域为{14}则这样的函数有个.
已知一次函数fx在R.上单调递增当x∈[03]时值域为[14].1求函数fx的解析式2当x∈[﹣18
若R上的奇函数y=fx的图象关于直线x=1对称且当0<x≤1时fx=log2x则方程在区间2010
4020
4022
4024
4026
设函数fx=log2x在区间05上随机取一个数x则fx<2的概率为
已知函数y=fx为奇函数且对定义域内的任意x都有f1+x=-f1-x.当x∈23时fx=log2x-
①②④
②③
①④
①②③④
已知函数fx为R.上的偶函数gx为R.上的奇函数且fx+gx=log44x+1.1求fxgx的解析式
已知定义在R上的偶函数fx在[0+∞上单调递减在[﹣44]上随机地取一个数x则事件不等式fx﹣1≥
已知二次函数fx=x2-x-6在区间[14]上的图象是一条连续的曲线且f1=-60由零点存在性定理可
已知fx是定义在R.上的偶函数且fx在[0+∞上为增函数f2=0则不等式flog2x>0的解集为__
在y=2xy=log2xy=x2y=cos2x这四个函数中当0
0
1
2
3
热门试题
更多
AsaprofessoratalargeAmericanuniversitythereisaphrasethatIhearoftenfromstudentsI'monlya1050.TheunluckystudentsarespeakingofthescoreontheScholasticAptitudeTestSATwhichisusedtodeterminewhethertheywillbeadmittedtothecollegeoruniversityoftheirchoiceorevenhaveachancetogetahighereducationatall.TheSATscorewhetheritis8001100or1550hasbecomesthefocusatthistimeoftheirlife. Itisobviousthatifstudentsvaluehighlytheirtestscoresthenagreatamountoftheirself﹣respectisputinthenumber.Studentswhoperformpoorlyontheexamareleftfeelingthatitisallover.Thelowtestscoretheythinkwillmakeitimpossibleforthemtogetintoagoodcollege.Andwithoutadegreefromaprestigiousuniversitytheyfearthatmanyoflife'sdoorswillremainforeverclosed. Accordingtoastudydoneinthe1990stheSATisonlyareliableindicatorofastudent'sfutureperformanceinmostcases.Interestinglyitbecomesmuchmoreaccuratewhenitissettogetherwithotherindicators﹣﹣likeastudent'shighschoolgrades.EvenifstandardizedtestsliketheSATcouldshowastudent'sacademicproficiency学业水平theywillneverbeabletotestthingslikeconfidenceeffortsandwillpowerandareunabletogiveusthefullpictureofastudent'spotentialities潜力.ThisisnottosuggestthatweshouldstopusingSATscoresinourcollegeadmissionprocess.TheSATisanexcellenttestinmanywaysandthescoreisstillausefulmeansoftestingstudents.Howeveritshouldbeonlyoneofmanymethodsused. 1ThepurposeoftheSATistoteststudents'. A.strongwill B.academicability C.fullpotentialities D.confidenceinschoolwork 2Students'self﹣respectisinfluencedbytheir. A.scoresintheSAT B.achievementsinmathematic C.jobopportunities D.moneyspentoneducation 3Aprestigiousuniversityismostprobably. A.afamousuniversity B.atechnicaluniversity C.atraditionaluniversity D.anexpensiveuniversity 4Thispassageismainlyabout. A.howtopreparefortheSAT B.stresscausedbytheSAT C.Americanhighereducation D.theSATanditseffects
Hehasreachedthepointhecansolvealmosteverysoftwareproblemhiscolleaguesmaymeetindailywork. A.Which B.when C.where D.that
按如图装置进行实验下列推断正确的是
11﹣二环丙基乙烯是重要医药中间体下列关于该化合物的说法错误的是
FromtheWhiteHousebalconyPresidentDonaldTrumpFirstLadyMelaniaTrumpandtheEasterBunnywelcomedthousandsofchildrenmembersofthemilitarystaffvolunteersandfamiliestothe139thannualEasterEggRollonMondayApril17.Thinkofit139.Itbeganalongtimeago1878PresidentTrumptoldthecrowd.Andwewillbestrongerandbiggerandbetterasanationthaneverbefore.Hethankedthemanyvolunteerswhorenewedthiswonderfultradition. TheannualEasterEggRollhasitsrootsinthe1800swhenlocalschoolchildrenonspringbreakwouldplayontheCapitolgroundsandholdhard﹣boiledeggracesdownCapitalHill.ThistraditionendedwhenCongresspassedtheTurfProtectLawbanningchildrenfromusingthegroundsastheirplayground.In1878PresidentRuthfordB.HayesbegantoformallywelcomechildrentotheWhiteHousegroundseachyearatEaster. Theeggrollin2017seemedtoputtogetherthreethemeschildrenfamilyandthemilitary.ThereweremilitaryfamiliesmultiplemilitarybandsandamilitaryofficersingingtheU.S.nationalanthem.AttheOperationThankOurTroopsstationchildrenandfamiliescouldcolorcardstosendtosoldiersservingoverseas.Conwaythepresident'scounselorbroughtherchildrentotheeggrollandhighlightedthechallengeofwork﹣familybalance.Thehardestpartofmyjobisbeingawayfrommyfourchildren.shesaidHelpingthenation. DuringtheEasterEggRollparentsstruggledtokeepupastheirchildrenrolledbrightly﹣coloredeggswithwoodenspoonsdowntheSouthLawn.Outsideoftherollkidsplayedsoccer.Somedancedtothemusic.ManykidstookturnstakingphotoswithpopularcharacterssuchasElmoDr.Seuss'sCatintheHattheTeeenageNinjaTurtlesandPeppaPig. TheReadingNookwasaparticularlypopularspotforchildrenwholistenedquietlyasMelaniaTrumpreadachildren'sbookaloud.TheFirstLadysaidshechosetoreadthebookPartyAnimalsBecauseitshowsthatwearealldifferentbutweareallthesame.WhenaskedaboutherfavoritepartofhernewroleasFirstLadyshesaid.Servingthecountry.It'sanhonorhelpingpeopleinthisgreatnation. 1WhatstoppedtheEasterEggRolltraditioninhistory? A.Theoutbreakofwar B.Thereductionofeggs C.Theadoptionofalaw D.TherepairingofCapitalHill 2HowdidConwayfindherwork? A.Difficultandboring B.Pioneeringandcomplex C.Dangerousbutmeaningful D.Demandingbutworthwhile 3Whatcanbeinferredaboutthe2017EasterEggRoll? A.Itfeaturedcolorfulandinterestingactivities B.Itstrengthenedthenation'sfamilyvalues C.Itcalledonpeopletodomilitaryservice D.Itstressedtheimportanceofreading 4Whatisthebesttitleforthetext? A.Adayforthekids B.Atraditionrollson C.Thefunoffestivalactivities D.ThestoryoftheEasterEggRoll
丙烯C3H6是重要的有机化工原料.丙烷脱氢制丙烯发生的主要反应及能量变化图如图1. 1丙烷脱氢制丙烯为强吸热过程为提供反应所需热量恒压时向原料气中掺入水蒸气. ①K主反应填“增大”“减小”或“不变”下同αC3H8. ②温度升高副反应更容易发生的主要原因是填“Ea1>Ea2”或“△H1>△H2”. 2图2为丙烷直接脱氢法中丙烷和丙烯的平衡体积分数与温度压强的关系其中压强分别为l04Pa和l05Pa. ①l04Pa时’图中表示丙烯的曲线是填“i”“ii”“iii”或“iv”. ②l04Pa500℃时主反应用平衡分压代替平衡浓度表示的化学平衡常数Kp=已知气体分压=气体总压×体积分数. 3利用CO2的弱氧化性开发了丙烷氧化脱氢制丙烯的新工艺.该工艺可采用铬的氧化物为催化剂其反应机理如图3. 已知 CO和H2的燃烧热△H分别为﹣283.0kJ•mol﹣1﹣285.8kJ•mol﹣1. ①图2中催化剂为. ②298K时该工艺总反应的热化学方程式为. ③该工艺可以有效消除催化剂表面的积炭维持催化剂活性原因是.
苯丙咪唑及其衍生物具有良好的生物活性而且是一种重要的药物中间体一种苯丙咪唑衍生物W的合成路线如下 已知 1A的化学名称是. 2④的反应类型是. 3①所需的化学试剂及反应条件是. 4写出C→D过程中的第一步的反应方程式. 5E中核磁共振氢谱中峰面积比具有两种官能团的四取代芳香化合物Q是E的同分异构体其可以与NaHCO3反应Q共有种不含立体异构. 6设计由乙二醛和12﹣二硝基苯为起始原料制备的合成路线无机试剂任选.
Oncoolspringmorningsyou'llfindfarmersacrossYunnanprovincefollowingtracks1wearbyyearsandyearsoffootstepsinthepre﹣dawnlight.Theirpinkraincoatsstand2inthemistyhillsidescoveredingreenplants. 3theydestination?Smallplotsofteabusheslocatedinclearingsamongtheoak﹣dottedhillsideswherethefirstwarmbreathofspringhassenttwofresh4leafspreadingouttotheedgeofeachbranch.Theteaharvestedinspringandagaininfall5beavitalsourceofincomeforfarmersinYunnanprovinceoneofChina's6littledevelopedprovinces. Whenthetimeisrightfarmerswillprocessthosetwintips7someofthefinestteaintheworld8fetchmorethan﹩100perpoundforthehighestqualityteas.Andthetimingiseverythingrightdowntothehour. Theamountofeffortfarmershaveputinoverhundredsofyearshasreallycreated9widevarietyofteaproductsandproductionmethods.It'ssomethinglike10scienceexperimentsthey'rejustdoingitheartandsoulandseeingwhathappens.
﹣﹣﹣WhereisMary? ﹣﹣﹣Ohshewentoutafterbreakfastandherpaperinthelibraryeversince.Youcanfindherthere. A.Wrote B.hadwritten C.hasbeenwriting D.iswriting
尼龙材料是一种性能优良的工程塑料目前广泛应用于汽车领域具有优异的力学性能.以AC6H10原料通过氧化反应制备G再通过缩聚反应合成尼龙合成路线如下 回答下列问题 1A的化学名称为 2B到C的反应类型为 3D中含有的官能团名称是 4E的分子式为 5由G合成尼龙的化学方程式为 6写出一种与C互为同分异构体的酯类化合物的结构简式核磁共振氢谱为两组峰峰面积之比为31. 714﹣二溴环己烯是多数有机合成一种重要的中间体设计由B为起始原料制备14﹣二溴环己烯的合成路线.
Todayisthebestdayofmylife!Almyyearsoftrainingasanengineerhasfinally. A.tookover B.pickedup C.paidoff D.paidfor
Languageispartofourdailylivesnomatterwhereweliveintheworld.Itisthesamewithmusicwhetheryoulistentoitontheradioonyourdrivetoworkorsitbeforeanorchestra.Bothlanguageandmusicplayahugeroleinourculture.1 Bothlanguageandmusichaveawritingsystem. InEnglishwerecordlanguageusingthealphabetwhichisacollectionofletters.Inthesamewayweusenotestokeeparecordofmusic.Justasyouarereadingthiscollectionoflettersonthescreenandfindmeaninginitmusiciansreadnotesandcreatemeaningintheformofmusic.2Bywritingpiecesoftextormusicweareabletoshareexperiencesthroughtime.Icanreadtheideasorhearthecompositionofsomeonewholivedhundredsofyearsagowhichisreallyquiteexciting. 3 Youcanmakeagoodguessatwheresomeoneisfrombylisteningtothelanguagetheyuse.Inthesamewaystylesofmusicaredifferentaroundtheworldgivingustheopportunitytoexploremanydifferentculturesthroughtheirmusicandprovidinguswithmusicforeverysituation.4Evenifyoudon'tlikeBritpopmelodiesyoumaylovetheenergyofLatinAmericansalsamusic. Bothshareemotion. HowdoyouknowthatIamangry?5butyouwillknowforsurethroughmywords.Similarlymusiccansoundangrysadorhappy.Musiccanshowyouexactlyhowthecomposerwasorisfeelingandallowsustoshareinthatemotion.Whenyoufeelhappyyoumightwanttosinganddancetoahappysongtocelebrateyourhappiness.Incontrastyouhaveprobablyalsolistenedtosadmusicwhenyouwerefeelingdown. A.Bothvarywithculture. B.Herearesomeoftheirsimilarities. C.UsuallyIneversayanythingaboutit D.Ofcourseyoumaybeabletoseeitinmyface E.SojustasyoureadEnglishyoucanreadmusic. F.Thisalsomeansthatthereissomethingforeveryone! G.Thisalsomeanseveryonecanlearnlanguageandmusicwell!
叠氮化钠NaN3常用作汽车安全气囊中的药剂.实验室制取叠氮化钠的原理实验装置及实验步骤如下 ①打开装置D导管上的旋塞加热制取氨气. ②再加热装置A中的金属钠使其熔化并充分反应后再停止加热装置D并关闭旋塞. ③向装置A中b容器内充入加热介质并加热到210~220℃然后通入N2O. ④冷却向产物中加入乙醇降低NaN3的溶解度减压浓缩结晶后再过滤并用乙醚洗涤晾干. 已知Ⅰ.NaN3是易溶于水的白色晶体微溶于乙醇不溶于乙醚 Ⅱ.NaNH2熔点210℃沸点400℃在水溶液中易水解. 请回答下列问题 1装置B中盛放的药品为装置C的主要作用是. 2步骤①中先加热通氨气的目的是步骤②氨气与熔化的钠反应生成NaNH2的化学方程式为.步骤③中最适宜的加热方式为填“水浴加热”“油浴加热”. 3N2O可由NH4NO3在240~245℃分解制得硝酸铵的熔点为169.6℃则可选择的气体发生装置是填序号. 4生成NaN3的化学方程式为. 5图中仪器a用的是铁质而不用玻璃其主要原因是. 6步骤④中用乙醚洗涤的主要目的是. 7实验室用滴定法测定叠氮化钠样品中NaN3的质量分数①将2.500g试样配成500.00mL溶液.②取50.00mL溶液置于锥形瓶中加入50.00mL0.1010mol•L﹣1NH42CeNO36溶液.③充分反应后将溶液稍稀释向溶液中加入8mL浓硫酸滴入3滴邻菲啰啉指示液用0.0500mol•L﹣1NH42FeSO42标准溶液滴定过量的Ce4+消耗溶液体积为29.00mL.测定过程的反应方程式为2NH42CeNO36+2NaN3=4NH4NO3+2CeNO33+2NaNO3+3N2↑Ce4++Fe2+=Ce3++Fe3+试样中NaN3的质量分数为.
甲醛在木材加工医药等方面有重要用途.甲醇直接脱氢是工业上合成甲醛的新方法制备过程涉及的主要反应如下 反应ICH3OHg⇌HCHOg+H2g△H1=+85.2kJ•mol﹣1 反应IICH3OHg+O21⇌HCHOg+H2Og△H2 反应IIIH2g+O2g⇌H2Og△H3=﹣241.8kJ•mol﹣1 副反应 反应IVCH3OHg+O2g⇌COg+2H2Og△H4=﹣393.0kJ•mol﹣1 1计算反应Ⅱ的反应热△H2=. 2750K下在恒容密闭容器中发生反应CH3OHg⇌HCHOg+H2g若起始压强为P0达到平衡转化率为α则平衡时的总压强P平=用含P0和α的式子表示当P0=101kPa测得α=50.0%计算反应平衡常数Kp=kPa用平衡分压代替平衡浓度计算分压=总压×物质的量分数忽略其它反应. 3Na2CO3是甲醇脱氢制甲醛的催化剂有研究指出催化反应的部分机理如下 历程iCH3OH→H+•CH2OH 历程ⅱ•CH2OH→•H+HCHO 历程ⅲ•CH2OH→3•H+CO 历程iv•H+•H→H2 如图表示一定条件下温度对碳酸钠催化脱氢性能的影响回答下列问题 ①从平衡角度解析550℃﹣650℃甲醇生成甲醛的转化率随温度升高的原因 ②反应历程i的活化能填“>“<”或“=”CH3OHg⇌HCHOg+H2g活化能. ③650℃~750℃反应历程ii的速率填“>”“<”或“=”反应历程ⅲ的速率. 4吹脱是处理甲醛废水的一种工艺吹脱速率可用方程v=0.0423cmg•L﹣1•h﹣1表示其中c为甲醛浓度下表为常温下甲醛的浓度随吹脱时间变化数据. 则当甲醛浓度为2000mg/L时其吹脱速率v=mg•L﹣1•h﹣1分析上表数据起始浓度为10000mg/L当甲醛浓度降为5000mg/L吹脱时间为h.
下列说法正确的是
﹣﹣﹣Itistoodifficultformetolearntoeatwithchopsticks. ﹣﹣﹣.Withmorepracticeyouwillsucceed A.It'suptoyou B.Nevermind C.Don'tloseheart D.It'shardtosay
Cockroachesarethemostunpleasantofallinsects.Seeminglylargeandfastandtheyliveinthemostdisgustingconditions. It'snowonderthefirstreactionofmanytoseeingacockroachistotrytodestroyitandfewwoulddropatearatthethoughtoftheentirespeciesdyingout. Butofcoursethingsarenotsosimple.Unpleasantthoughtheyareaccordingtobiologiststheill﹣famedcockroachisessentialtothesurvivaloftheplanet'sdelicateecosystem. AccordingtoSriniKambhampatiprofessorandchairmanofthebiologydepartmentattheUniversityofTexasthedisappearanceofcockroacheswoulddoharmtothenitrogencycle. AsaleadingexpertonroacheshesaidMostcockroachesfeedonrottenorganicmatterwhichtrapsalotofnitrogen.Cockroachfeedinghastheeffectofreleasingthatnitrogenintheirwastewhichthengetsintothesoilandisusedbyplants.Inotherwordsextinctionofcockroacheswouldhaveabigimpactonforesthealthandthereforeindirectlyonallthespeciesthatlivethere. TheprofessoralsowarnedthattheEarth's5000to10000cockroachspeciesarealsoanimportantsourceoffoodformanybirdsandsmallmammalslikemiceandrats. Inturnthesekillersthemselvesarefoodofmanyotherspecieslikecatswolvesandsnakesaswellaseaglesandotherbigbirds. Anycuttothenumberofcockroacheswouldthushaveaharmfuleffectonthewellbeingofallthesespeciesthatcouldhaveadestroyingeffectonwildlifeacrosstheworld. Ofcoursethere'snotmuchchanceofacockroachextinction灭绝leveleventhappeninganytime soon.StillalthoughitwasoncebelievedthattheywouldbeoneofthefewcreaturestosurviveevenanuclearThirdWorldWarthatideahassincebeenconsidereduntrue. 1Whatisthemainideaofthispassage? A.Thehatedcockroachisessentialtothesurvivaloftheplanet'sdelicateecosystem. B.Thecockroachisaharmfulspecieswhichisexpectedtodieoutinthenearfuture. C.Nobodywillfeelsadatthefactthattheentirespeciesofcockroachisdyingout. D.Let'sdestroycockroacheswithoutmercybecausetheypollutedtheenvironment. 2FromwhatProfessorKambhampatisaidinParagraph5wecanlearnthat. A.cockroacheseatrottenorganicmattertotrapnitrogen B.nitrogencanmakethesoilsuitableforplantstogrow C.toomanycockroachesmightdestroyotherspecies D.plantsbenefitfromcockroaches'enteringthesoil 3WhichofthefollowingbelongtothesekillersinParagraph7? A.Cockroaches. B.Catsandwolves. C.Miceandrats. D.Snakesandeagles. 4Wecaninferfromthelastparagraphsthatcockroaches. A.mightcauseothercreaturestodieout B.cansurviveanuclearwar C.mightdieoutinextremecircumstances D.willneverbeextinctatall
煤的电化学脱硫是借助煤在电解槽阳极发生的电化学氧化反应将煤中黄铁矿FeS2或有机硫化物氧化成可溶于水的含硫化合物而达到净煤目的如图是一种脱硫机理则下列说法正确的是
AbouttwoweeksbeforeChristmasof2014mywifeboughtmeanearlyChristmaspresent.Itwasabeautifulthree﹣month﹣oldcockatiel鸡尾鹦鹉. Ihadalways1forabirdbutasmywifehadobjectedtotheveryideaofgettingoneIwasreally2whenshebroughtherhome.IimmediatelyfellinlovewithherandnamedherBleng. FromthebeginningIwas3bytheownerofthepetshopnottoputa4inhercageasshewouldthinkthatthereflectionwasanotherbird.ThiscouldcauseBlengtobecome5asthereflectionwouldn'treacttoher. 6mylittleBleng7reflectivesurfacesaroundthehouseallonherowninthekitchenagainsttherefrigeratoretcShespreadherwingsoutslightlyeverytimeshe8herreflectionandshespentalotoftimearoundthese9. Butitwasn'tuntillastJulywhenweboughtamirroredbedsidetableformymother﹣in﹣law'sroomthatthingsreallybecame10. Bleng11spendingtimearoundthisbedsidetableandaroundhernew12! Onedaymymother﹣in﹣lawwenttoherroomandnoticedareal13.Seedswerescatteredallaroundthebedsidetable.She14Blengrunningtohercagewhichwasinanotherroomand15carryingseedstothebedsidetableandsettingthemdownonthe16.Blenghadnoticedthatherreflection17wenttotheseedbowltoeat18shebroughttheseedsovertoherfriend! WehadalwaysknownthatBlengwasa19creaturebutitwasatthatmomentthatwealllearnedjusthow20herheartreallywas! 1A.prepared B.longed C.waited D.looked 2A.frightened B.relaxed C.worried D.surprised 3A.advised B.allowed C.invited D.urged 4A.bowl B.bird C.mirror D.seed 5A.satisfied B.proud C.afraid D.disappointed 6A.Besides B.However C.Instead D.Therefore 7A.spotted B.collected C.checked D.made 8A.ignored B.remembered C.saw D.doubted 9A.animals B.areas C.rooms D.people 10A.amusing B.confusing C.complex D.annoying 11A.avoided B.regretted C.missed D.enjoyed 12A.master B.friend C.cage D.tool 13A.mess B.trend C.chance D.crowd 14A.imagined B.stopped C.observed D.kept 15A.escaping B.hiding C.considering D.returning 16A.ground B.bed C.mirror D.paper 17A.already B.also C.never D.still 18A.or B.so C.for D.but 19A.huge B.dangerous C.poor D.loving 20A.cold B.heavy C.big D.weak
Don'tfocusonwhatyou'relacking.Insteadyoushouldbewithwhatyou'vealreadyhad. A.content B.busy C.patient D.strict
Manymovedstoriesremaindeepinpeople'shearttothisday.In2008aterribleearthquakestrikeWenchuantheremanypeoplelosttheirlivesandhomes.Aftertheearthquakeunderafallenbuildingamotheraswellasherbabywerefoundbysomesoldiers.Whenthesoldierswerereadytotakethemawaytheysurprisedtofindthebabyinthemother'sarmsstillalive.Thebabywassleepingbutwasn'thurtatall.Betweenthedeadmotherandthelivingbabytherewasacellphonewithashortmessageonthescreen.ItreadDon'tworrymybaby.Momisforyou.Ifyoucansurvivedon'tforgetthatIloveyou. Thestorymovedmanypeopledeepincludingme.Icouldn'tholdbackmytearswhenIreadtheseword.Oneisgreatifhelovesotherswhenheisinthedanger.
工业用空气氧化NH42SO3的方法制取NH42SO4研究小组用如图装置模拟该过程并通过测定反应后溶液中SO32﹣的浓度来计算该反应的转化率. 实验步骤 ①按图连接好装置检查气密性 ②取200mL0.5000mol/L的NH42SO3溶液含有一定量氨水pH=8装入三颈烧瓶中加入催化剂控制气体流速为300L/h控制温度在50℃进行实验 ③反应2.5小时后测定反应后溶液中SO32﹣的浓度. 回答下列问题 1仪器a的名称是. 2装置B的作用是. 3C中NH42SO3被氧化该反应的离子方程式为装置C中的反应需要控制温度在50℃采用的实验措施是C中溶液的pH不能低于8原因是. 4取20.00mL反应后的溶液于碘量瓶中滴入3滴淀粉溶液用0.1000mol/L的标准碘溶液滴定至终点消耗碘水体积为18.50mL则NH42SO3的转化率为. 5指出实验装置存在的缺陷写一条
目前研究比较热门的Al﹣H2O2电池其电池总反应为2Al+3HO2﹣=2AlO2﹣+OH﹣+H2O.现以AlH2O2电池电解尿素[CONH22]的碱性溶液制备氢气装置2中隔膜仅阻止气体通过bcd均为惰性电极.下列说法错误的是
假定你是李华你的英国笔友Mark在中国某大学学习.近日他发email给你说他迷上了中国诗词手头有三本诗词集诗经TheBookofOdes唐诗三百首300TangPoems 宋词三百首300SongLyrics想请你从中给他推荐一本作为起步读本.请你用英语给他回复email要点如下 1.选定推荐书目 2.简单介绍内容 3.说明推荐理由.注意1.词数100左右 2.可以适当增加细节以使行文连贯. HiMark Thankyouforyouremailwhichtellsmethatyou'reconfusedaboutwhichbooktochooseforyourpoemlearning. Bestwishes! Yours LiHua
HowamazingitisthatZuckbergcanspeakChinese!Afterallitisabigforanywesternertolearnsuchatotallydifferentlanguage. A.adventure B.achievement C.trend D.challenge
Atimelineofairdisasters March112019AnEthiopianAirlinesflightBoeing737fromAddisAbabatoNairobiKenyacrashedsoonaftertakingoffonSundaymorningkillingall157peopleonboardincluding8Chinese. May182018AplanerentedbylocalcompanyCubanadeAviacionfromtheMexicanairlineDamojhcrashedshortlyaftertakingofffromHavana'sJoseMartiInternationalAirport.Atotalof114peoplewereonboardamongwhomtwowomensurvived. November52017aCzech﹣builtLet410belongingtoKhabarovskAviacrashedonlandingat NelkanintheRussianFarEastwiththelossofsixlives.Afour﹣year﹣oldgirlwastheonlysurvivor. May182016EgyptAirFlightMS804CrashesintoMediterraneanSeacausing57deathsincludingonechildandtwobabies. March242015GermanwingsFlight9525with150passengersandcrewcrashedintheFrench AlpsonthewayfromBarcelonatotheGermancityofDuesseldorf.Allonboardwerekilled. March82014MalaysiaAirlinesFlight370disappearedlessthananhouraftertakeoff.TheplanewastravelingfromKualaLumpurInternationalAirporttoBeijing.ItvanishedovertheIndianOceanwith 239passengersandcrewmembersonboard. November172013TatarstanAirlinesBoeing737crashesonlandinginKazanRussiakillingall 50peopleonboard. April202012ABhojaAirBoeing737crashesonitsapproachtothemainairportinthePakistanicapitalIslamabadkillingall121passengersandsixcrew. January92011AnIranAirBoeing727breaksintopiecesnearthecityofOrumiyehkilling72onthesceneandinjuring33fiveofwhomdiedlaterinhospital.Thepilotshadreportedatechnicalfailurebeforetryingtoland. May222010AnAirIndiaExpressBoeing737overshottherunwaywhilelandingatahilltopairportandcrashedintoavalleyburstingintoflamesandleaving159deathsand7injuries. 1Whichyearinthelistwasthesafestyearforairpassengers? A.2017. B.2015. C.2013. D.2011. 2Inthislistwhichofthefollowinginvolvedthemostcrashes? A.Takingoff. B.Landing. C.Boeing737. D.ThemonthofMarch. 3Howmanypeopleescapedfrombeingkilledinthe10airdisasterslistedabove? A.3. B.36. C.38. D.43.
甲胺铅碘CH3NH3PbI3可用作全固态钙钛矿敏化太阳能电池的敏化剂由CH3NH2PbI2及HI为原料合成回答下列问题 1制取甲胺的反应为CH3OHg+NH3g⇌CH3NH2g+H2Og△H.已知该反应中相关化学键的键能数据如下 则该反应的△H=kJ•mol﹣1. 2上述反应中所需的甲醇工业上利用水煤气合成反应为COg+2H2g⇌CH3OHg△H<0.在一定条件下将1molCO和2molH2通入密闭容器中进行反应当改变某一外界条件温度或压强时CH3OH的体积分数φCH3OH变化趋势如图1所示 ①下列说法不能判断该反应达到化学平衡状态的是. A.体系中气体的密度保持不变B.CO的消耗速率与CH3OH的消耗速率相等 C.体系中CO的转化率和H2的转化率相等D.体系中CH3OH的体积分数保持不变 ②平衡时M点CH3OH的体积分数为10%则CO的转化率为. ③某同学认为上图中Y轴表示温度你认为他判断的理由是. 3实验室可由四氧化三铅和氢碘酸反应制备难溶的PbI2同时生成I2写出发生的化学反应方程式. 4HI的制备将0.8molI2g和1.2molH2g置于某1L密闭容器中在一定温度下发生反应I2g+H2g⇌2HIg并达到平衡.HI的体积分数随时间的变化如表格所示 ①该反应的平衡常数K=. ②反应达到平衡后在7min时将容器体积压缩为原来的一半.请在图2中画出cHI随时间变化的曲线.
Thefutureofourcitythecreativityandinnovationofyoungpeople. A.takesin B.liesin C.resultsin D.bringsin
工业生产苯乙烯是利用乙苯的脱氢反应 下列说法正确的是
聚乙烯醇肉桂酸酯M可用作光刻工艺中的抗腐蚀涂层其合成路线如下 请回答 1B的化学名称为M中含氧官能团的名称为F→G的反应类型为. 2C→D的化学反应方程式为. 3E的结构简式为H的顺式结构简式为. 4同时满足下列条件的F的同分异构体有种不考虑立体异构①属于芳香族化合物②能发生水解反应和银镜反应.写出其中一种核磁共振氢谱有4种吸收峰其峰面积之比为6211的物质的结构简式. 5参照上述合成路线和相关信息以乙烯和乙醛为原料无机试剂任选合成有机物设计合成路线.
热门题库
更多
高二上学期物理
高二上学期英语
高二上学期生物
高二下学期数学
高二上学期化学
高二下学期物理
高三下学期物理
高三上学期物理
高三上学期生物
高三上学期化学
高二下学期化学
高二下学期生物
高三下学期生物
高三下学期化学
高三上学期英语
高二下学期英语