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已知：一元弱酸HA的电离平衡常数K ＝．25℃时，CH3COOH、HCN、H2CO3的电离平衡常数如表：下列说法正确的是（ ）
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已知0.01mol·L-1的某一元弱酸的pH=4则它的电离平衡常数为_____
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离下列叙述错误的是
该溶液的pH=4
由HA电离出的c(H
+
)约为水电离出的c (H
+
)的10
6
倍
此酸的电离平衡常数约为1×10
-7
升高温度，溶液的pH增大
下列关于电离平衡常数K.的说法中正确的是
电离平衡常数越小，表示弱电解质的电离能力越弱
电离平衡常数与温度无关
不同浓度的同一弱电解质，其电离平衡常数不同
多元弱酸各步电离平衡常数相互关系为：K
1
〈K
2
〈K
3
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离回答下列问题1该溶液中cH＋＝____
将0.05mol·L－1的盐酸和未知浓度的NaOH溶液以12的体积比混合后pH＝12用上述NaOH
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离回答下列各问题1该溶液的cOH－＝__
对于弱酸在一定温度下达到电离平衡时各微粒的浓度存在一种定量的关系若25℃时有HAH++A―则K.=式
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离下列叙述错误的是
该溶液的pH值约为4
此酸的电离平衡常数约为1×10
－7
升高温度，溶液pH增大
由HA电离出的c(H
＋
)约为水电离出的c(H
＋
)的10
6
倍
已知室温时0.1mol·L－1的某一元酸HA在水中有0.1%发生电离回答下列各问题1该溶液的pH＝_
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离回答下列问题1该溶液中cH+=.2HA
已知某温度下四种一元弱酸的电离平衡常数为KaHCN＝6.2×10-10mol/LKaHF＝6.8×1
HCN
CH
3
COOH
HF
HNO
2
已知室温时0.1mol·L.－1的某一元酸HA在水中有0.1%发生电离回答下列各问题1HA的电离平衡
下列关于电离平衡常数K.的说法中正确的是
电离平衡常数（K.）与温度无关
H
2
CO
3
的电离常数表达式
同温下，电离平衡常数越小表示弱电解质电离能力越弱
多元弱酸各步电离平衡常数相互关系为：K
1
2
3
已知室温时0.1mol/L某一元酸HA在水中有1%发生电离回答下列问题1该溶液中cH＋＝______
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离回答下列各问题1HA的电离平衡常数K.
一定温度下用水稀释0.1mol·L.－1的一元弱酸HA随稀释进行下列数值增大的是Kw表示水的离子积K
K
w
c(OH
－
)
下列关于电离平衡常数K.的说法正确的是
不同浓度的同一弱电解质，其电离平衡常数（K.）不同
电离平衡常数（K.）越小，表示弱电解质电离能力越弱
多元弱酸各步电离平衡常数相互关系为：K.
1
＜K.
2
＜K.
3
CH
3
COOH溶液中加入少量CH
3
COONa溶液，电离常数减小
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离下列叙述错误的是
该溶液的pH＝4
升高温度，溶液的pH增大
此酸的电离平衡常数约为1×10
－
7
由HA电离出的c(H
＋
)约为水电离出的c(H
＋
)的10
6
倍
已知室温时0.1mol/L某一元酸HA在水中有0.1%发生电离下列叙述错误的是
该溶液的pH＝4
升高温度，溶液的pH增大
此酸的电离平衡常数约为1×10－7
由HA电离出的c（H.＋）约为水电离出的c（H.＋）的106倍
已知室温时0.1mol/L的一元酸HA在水中有0.1%发生电离下列叙述错误的是
溶液的PH＝4
升高温度，溶液PH增大
此酸的电离平衡常数为1×10
－7
由HA电离的c(H
+
)约为水电离出来的c(H
+
)的10
6
倍
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ThanksgivingDayisspecialholidayintheUnitedStatesandCanada1. ThanksgivingDayisreallyaharvestfestival.Thisiswhyitiscelebratedinlatefallafterthecropsarein2.OnDecember41619thePilgrimsfromEnglandlandednearwhatisnowCharlesCityVirginia.TheykneltdownandthankedGodfortheirsafejourneyacrosstheAtlantic. 3ThePilgrimslandedatwhatisnowPlymouthMassachusettsin1620.Theyhadadifficulttimeandthefirstwinterwascruel.ManyofthePilgrimsdied.Butthenextyeartheyhadagoodharvest.SoGovernorBradforddeclaredathree﹣dayfeast盛宴.4Everyonebroughtfood. Intimeothercolonies殖民地begantocelebrateadayofthanksgiving.ButittookyearsbeforetherewasanationalThanksgivingDay.DuringtheCivilWarSarahJosephaHalepersuadedAbrahamLincolntodosomethingaboutit.5TodayAmericanscelebratethishappyharvestfestivalonthefourthThursdayinNovember.CanadianscelebrateThanksgivingDayinmuchthesamewayastheirAmericanneighbours.ButtheCanadianthanks﹣givingDayfallsonthesecondMondayinOctober. A.ButoneofthefirstthanksgivingsinAmericahadnothingtodowithagoodharvest. B.HedeclaredthelastThursdayofNovember1863asadayofthanksgiving. C.ThePilgrimswerethosewhocelebratedthefirstThanksgivingDay. D.Familiesandfriendsgathertoeatandgivethanksfortheirblessing. E.ThePilgrimsinvitedIndianfriendstojointhemfortheirspecialfeast. F.ThisiswhyhedecidedtomakeitanationalholidaythroughouttheU.S.. G.ThefirstNewEnglandThanksgivingdidcelebratearichharvest.
Bitcoinandotherso﹣calledcryptocurrencies加密货币havebeenalloverthenewslately.Apparentlytheideaofmoneythat'snottiedtoaspecificbankoraspecificcountryisappealingtomany.Andmoreandmorepeopleshowtheirinterestinthesecryptocurrencies. Inthepastmoney'smakeupvariedfromplacetoplace.Variousobjectshaveservedascurrencyincludingbeadsivoryandshells.InWestAfricabracelets手镯ofbronzeorcopperconsideredtohavegreatworthwereusedascashespeciallyifthebusinesswasassociatedwiththeslavetradethere.ThroughoutthecolonialperiodwhentobaccowasplantedgreatlyandbroughtbigeconomicbenefitsitwasusedinplaceofcoinsorpaperbillsinVirginiaMarylandandNorthCarolina. TodayonMalaitaanislandinthePacificaspecifictypeofshellstillservesascurrencyandsomepeoplethereareevenhoardingitjustlikeBitcoinconvincedthatonedayitwillmakethemwealthybeyondimagination.MaryBrunoashopownerfromthesmalltownofAukionMalaitasaidoneofdarkershellsmightgetyouabouttwocansoftuna金枪鱼butoneofredshellsmightgetenoughtunatofeedabigfamilyforalongtime.Justlikeaplacethatcreatescoinsthere'sonlyoneplaceontheislandwheretheshellswhicharepolishedandstrungtogethertoform3﹣foot﹣longropesaremade.TheredwhiteandblackshellsallcomefromLangaLangaLagoonwhereartificialislandswerebuiltbylocalstoescapefromthewarlongago.Oncetrappedontheseislandslocalsneededacurrencytouseamongthemselvesandsotheshellcurrencywasborn. Justlikecryptocurrenciestherearethosewhothinktheislandersaresmarttoinvestinthistypeofmoneywhichisreportedtohaveriseninvalueoverthelastthreedecades.Itmightseemstrangebutwhatisapileofdollars?It'sjustaspeciallyprintedpieceofpaperthatwe'veassignedvalueto﹣﹣andprobablylessdurable耐用overtimethanthoseshells. 1WhatdoestheauthorintendtotellusinParagraph1? A.Atrendofcurrency. B.People'sinterestinBitcoin. C.Banks'controlovercurrency. D.Aneffectofcryptocurrencies. 2TheunderlinedwordhoardinginParagraph3canbereplacedby. A.selling B.polishing C.collecting D.hiding 3Accordingtothispassagewhatdeterminesthevalueofshells? A.Theircolor. B.Theirshape. C.Theirsource D.Theirweight. 4Whatistheauthorsattitudetowardstheislanders'investinginshells? A.Doubtful. B.Objective. C.Uncaring. D.Approving.
假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文.文中共有10处错误每句中最多有两处.错误涉及一个单词的增加删除或修改. 增加在缺词处加一个漏词符号∧并在其下面写出该加的词. 删除把多余的词用斜线﹨划掉. 修改在错的词下划一横线﹣﹣﹣﹣﹣并在该词下面写出修改的词. 注意1.每处错误及修改均仅限一词 2.只允许修改10处多者从第11处起不计分. LastnightourschoolorganizedanEnglishCorner.Iwenttherewithdozenofstudentsmostofthemwereseniors.AndtherewasalsonativeEnglishspeakerwhowasinvitedtocommunicatewithus.Hewasveryhumorousandeasy﹣goingbutlovedansweringquestionsraisebystudents.ItwasthefirsttimethatIhaveattendedanEnglishCorner.Ididn'taskforasinglequestionbecauseIwasreallynervousandpooratspokenEnglish.SoIjustlistenedtohertalkingwithotherstudents.IwasdeterminedtopracticingspeakingEnglishashardasIcouldhopingtocommunicatewithforeignersfluentinEnglishinthefuture.
Englishisnowthefirstlanguageofabout400millionpeoplethemotherlanguageof12countriesandtheofficiallanguageofone﹣fifthofthelandareaoftheworld1meansone2everysevenpeopleintheworldspeaksEnglish. Moreandmorepeoplehavefounditimportant3learnEnglishwellinrecentyears.InItalyforexampleEnglishisamustformanytechnicaljobs.InChinaEnglishisthe4importantforeignlanguagethatislearnedatschool. TheEnglishlanguagehasneverstoppedchanging.Italwaysborrowswordsandphrasesfromotherculturestoenlarge5itvocabulary.6actualmodemEnglishisquitedifferentfromwhat7usehundredsofyearsago. Englishissowidelyusedthatithasbecomethestandardlanguagefor8communicateinternationally.About75%oftheworld'smail9beinEnglish.About60%oftheworld'stelephonecallsaremadeinEnglishandabout60%oftheworld'sradioprogramsarebroadcastinEnglish.What'smoreoverhalfoftheworld'sbooksandmagazinesarewritteninEnglish.In10wordEnglishisnowtheworld'sfirstlanguage.
Nooneknowswhomadethefirsticecream.SomepeoplethinkthatwatericesandmilkicesmayhavebeenmadebytheChinesebetweenthreethousandandathousandyearsago.InthattimethedishreachedIndia.TheIndiansinturnmanyhavepassedonthesecrettotheArabsandPersians. MarcoPoloanItalianwhotravelledwidelyinthethirteenthcenturynotedthathefoundtheChinesehadlongbeenmakingicesoutoffruitjuicesandmilk.FromthefourteenthcenturyonicesbecamepopularfirstinVeniceandthenthroughoutItaly. In1535whenCatherinedeMedeicisleftItalytomarrythefutureKingHerryIIofFranceshetookhercookswithher.TheymadedessertstheFrenchhadnevertastedbeforewhichwasicecream. AtfirsticecreamwasaluxuryinFrance.Onlyrichpeoplehadthemoneytobuyit.Thenin1660ayoungmanfromSicilyFranciscoProcopioarrivedinParis.Heopenedashopthatsoldicecreamatpricespeoplecouldafford.Thenhisicecreambecamesopopularthatothershopswereopened. About1640KingCharlesintroducedicecreamtoEnglandandsoonicecreamquicklybecamepopularinEnglandtoo. 1IcecreamwasunknowninFranceuntil. A.1660 B.1535 C.1774 D.1640 2WhointroducedicecreamtoEngland? A.KingCharles B.CatherinedeMedeicis C.FranciscoProcopio D.MarcoPolo 3Whatwillbeprobablytalkedaboutinthenextparagraphs? A.MarcoPolo'stravelintheworld B.Developmentoficecreaminothercountries C.DevelopmentoficecreaminEngland D.DevelopmentoficecreaminFrance 4What'sthispassagemainlyabout? A.MarcoPolo'stravel B.oneofChineseinventions C.Catherine'smarriage D.thehistoryoficecream
等比数列{an}中若a1＝1a5＝16则a2•a3•a4＝
现有两个小麦品种一个纯种小麦性状是高杆D抗锈病T另一个纯种小麦的性状是矮杆d易染锈病t．两对基因独立遗传．育种专家提出了如图所示的ⅠⅡ两种育种方法以获得小麦新品种．问 1方法Ⅰ与方法Ⅱ相比前者的优势在于． 2图中①和④基因组成分别为和． 3三过程采用的方法称为四过程最常用的化学药剂是五过程产生的抗倒伏抗锈病植株中的纯合体占．
已知函数fx＝x2+x+6存在x∈[02]使得fx≥a2﹣a成立则实数a的取值范围
下列有关细胞中的物质结构与功能的叙述中不正确的是
在△ABC中角ABC所对的边的长分别为abc若asinA+bsinB＜csinC则△ABC的形状是
某雌雄异株植物XY型性别决定花色由两对独立遗传的等位基因Aa和Bb控制两对基因控制有色物质合成关系如图取紫花雄株甲与白花雌株乙杂交F1红花雄株紫花雌株＝11．下列叙述正确的是
WhenAmericansKayandLarryDayfoundastoresellingkitesnearly20yearsagotheydecidedtobuyafewkitesfortheirfamily.ForfunLarryboughtoneforhimself.HewentoutandflewitanddecidedtogobackandaddmorefuntotheeventKayremembered. Sincethensheandherhusbandhavelovedkiteflying.Theyownmanykitesandplantripsaroundflyingthem.Theyalsoorganizeakite﹣flyingeventeachwinterintheirhometowninIowa.I'matpeacewhenI'mflyingakitesaidLarry. Kite﹣flyinghasalonghistoryasanactivityforadultsandchildren.Thecustomofflyingapieceofclothhighintheskybeganmorethan2000yearsagoinChina.Sincethenkiteshavebeenusedtodoscientificexperimentspowerboatstakepicturesfromtheairandmuchmore. Sometimesthebestflyingconditionshappeninwinter﹣onafrozenlakesaidKayDaywhowithherhusbandorganizestheColortheWindKiteFestival.IttakesplaceeveryFebruaryonClearLakeinIowa.Thefestivaladdscolortothewinterskyandgivespeopleareasontogooutsidesheadded.TheDaysinviteexpertflierstocomeandsharetheirloveforkiteswithlocalsandvisitors.Thisyearmorethan100childrenattendedakite﹣makingclass.Kitersareareallygoodgroupofpeople.It'safamilysaidLarry. Kaysaysthattheloveforkitescanspreadtootherseasily.ShesayshertwochildrenDylanandCardinstartedflyingkitesaboutthreeyearsagoafterattendingakitefestivaltheyheld.Theylikewatchingtheirparentsflykiteshappilytogether.Thesceneencouragesthemtoflykitesthemselves.IdoenjoyattendingkitefestivalsDylansaid.The13﹣year﹣oldboyenjoysitwhenhiskitemovesfreelythroughthesky. 1WhenLarryflewakite20yearsagohedecidedto. A.spreadhisloveforkitestohisfamily B.plantripstoflykites C.makekiteflyingmoreenjoyable D.holdakitefestival 2Whatdoesparagraph3mainlytalkabout? A.Kite﹣flyingactivitiesforkitelovers. B.Thehistoryofkites. C.Methodsofmakingakite. D.Theusageofkites. 3FromLarry'spointofviewthekitefestivalcan. A.attractmanyexpertsfliers B.maketheirhometownfamous C.bringpeoplemuchfreedom D.strengthenhumanrelations 4Whatcanbeinferredfromthelastparagraph? A.Childrenaregoodatflyingkites. B.Peopleofallagesloveflyingkites. C.Parents'interestscaninfluencetheirkids. D.Parents'skillsshouldbepassedontokids.
已知m∈R直线lmx﹣2+2y＝0恒过定点P则P的坐标为．
文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加在缺词处加一个漏词符号/\并在该句下面写出该加的词. 删除把多余的词用斜线\划掉. 修改在错的词下划一横线并在该词下面写出修改后的词. 注意1.每处错误及其修改均仅限一词2.只允许修改10处多者从第11处起不计分. Wheneverthereisanexamaroundthecornerit'snormaltofeelanxiously.Naturallyyouarelikelytobeinyourroomstudyashardasyoucanbeforethebigday.Asthematteroffactthecolorofyourroomcouldhaveaninfluenceontheresultofyourexam.Ithasfoundthatpalecolorslikeblueorlightgreenmakepeoplerelaxingandcalm.Asaresultourbraingetslazyandinactivebutbecomeslessopentotakinginalargeamountofinformations.Onthecontrarybrightcolorscanhelpusconcentrateonataskeasilyandsolveproblemsefficiently.That'sbecausetheymayrelieveourstressbycheeringthemup.Sonexttimeyouhadtodealwithadifficulttaskmakesureofyouchoosearoomwithabrightcolor.
PoliceForcepresentsCommunityRoadshow2019 Wanttofindoutmoreaboutpolicework?ComeandvisitusatthevariouslocationsacrossSingapore.EnjoytheperformancesbythefriendlydogsfromthePoliceK9UnitandthePoliceBand. Comewithyourfamilyandtakepartinthefunactivities. OrganizedbytheSingaporePoliceForce 1WhatshalleachparticipantgetinCommunityRoadshow2019? A.Afunpack. B.Someprize. C.SomeVoucher. D.BouncyCastle. 2HowshouldapersonsignupforArtCompetition? A.Onsite. B.Byemail. C.Byphone. D.ThroughtheInternet. 3Whichofthefollowingorganizedtheactivity? A.SerangoonCentre. B.RockClimbCompany. C.SingaporePoliceForce. D.PoliceortCompany.
WhenIwasfifteenyearsoldItoldmymotherIwantedcontactlenses隐形眼镜.Somegirlsatmyschoolhadgotthemandtheylooked1withouttheirglasses.MomtoldmethatIwouldhavetogetan2topayforthelensesmyself.When3herthatthelegalworkingagewassixteenshesaidthatshewouldaskherformer4ofagrocerystoretohiremeparttime.Shesaidthatshewasgreatly5andencouragedbyhimwhensheworkedthere. Ihad6earnedmoneybybabysittingrunningerrandsandshovelingsnow.Sothiswasmyfirstexperienceofworkingwithadults.OnmyfirstdayI7groceries.Everyitemhadtobeplacedtidilyinbrownpaperbags.EventuallyIwasgiventhe8ofrunningthesnackbar.Mydutymainly9makinghotdogsofferingsupplieslikefreshdonutsandpastriesand10customers.AsittookaboutanhourforthehotdoggrilltocooldownafterIshutitoffIwasusually11employeetoleavethestore.Iwasvery12incheckingmyworkareatoensurethat13wascleanandtheelectronicswere14beforeIwenthome.IlovedmyworktheresoI15workingatthegrocerystorethroughouthighschool. Thisexperiencefinallynotonlyhelpedmegetmycontactlensesbutalso16memanythings.Workingwithadultsgavemean17oftheirdailystrugglesandthe18ofbeingawifeandmotherwhileworkingfulltime.WhenIwasatworkIwas19likeanadultsoIhadtoworkhardformypaycheck.NowwhenIgoshoppingatgrocerystoresIespecially20theemployeesthere. 1A.morespecial B.moreintelligent C.prettier D.brighter 2A.chance B.approval C.plan D.job 3A.reminded B.persuaded C.warned D.reported 4A.student B.colleague C.boss D.relative 5A.blamed B.educated C.moved D.supported 6A.mainly B.previously C.fairly D.exactly 7A.checked B.counted C.bagged D.purchased 8A.present B.reward C.benefit D.responsibility 9A.deserved B.occupied C.involved D.devoted 10A.serving B.controlling C.finding D.pleasing 11A.last B.best C.first D.fastest 12A.strong B.nervous C.excited D.careful 13A.anything B.something C.everything D.nothing 14A.turneddown B.turnedoff C.turnedin D.turnedaway 15A.kept B.suggested C.practiced D.considered 16A.taught B.lent C.showed D.saved 17A.detail B.understanding C.method D.goal 18A.cost B.meaning C.happiness D.challenge 19A.hired B.treated C.encouraged D.punished 20A.respect B.praise C.envy D.impress
Switchingfromchildhoodtoadulthoodcanbechallenging.1Workonnotactinglikeachildbymanagingyouremotions.Withalitebitofpracticeyouwillbegintoseeyourselfactingmorelikeanadultthanachild ●Acceptresponsibilityforyouractions. Youshouldtakeresponsibilityforyouractionswhethertheyareintentional故意的orunintentional.2Failingtoacceptresponsibilitymayseemlikeagoodideaatthetimebutinthelongtermitwillnotbenefityou.Forexampleifyouaccidentallybackintoyourneighbor'scarletthemknowbywritingthemanoteorknockingontheirdoor.Thencorrectyourmistakebypayingforthedamage. ●Showpeoplerespect. Respectyourpartnerfamilymembersfriendsandstrangers.3Asyougrowupandmatureyoushouldunderstandtheconceptofrespectandwhyitisimportant.Givingrespectwillalsogiveyoumorerespectinreturn. ●Developawaytohandleconflictmaturely. Whenyouarefacedwithaconflictitisimportanttokeepyouremotionsincheck.Controlyourangerandavoidbecomingaggressive.4Giveyourselftimetocooldownifyouarerallyangry.Thiswillpreventyoufromsayinganddoingthingsthatyoushouldn'tdointheheatofthemoment. ●Receivefeedback反馈positively. Peoplelearnandgrowbyreceivingfeedbackandcriticismfromothers.Youshouldacceptthatyoudon'tknoweverythingandthatfeedbackfromanexpertisnotmeanttohurtyou.Itismeanttohelpyou.Forexamplethoroughlyreadthroughyoureditsonyourresearchpaper.5. A.Takeonadultresponsibilities. B.Oftentimesyoumaystillfeellikeachild. C.Childrenareoftenselfishanddisrespectful. D.Itisasignofmaturityandrespectforothers E.Theseeditswillhelpimproveyourwritinginthefuture. E.Thiscanhelpyougethighermarksinmanyofyoursubjects. G.Takeadeepbreathlistenandworkthroughtheconflictwiththeotherindividual.
Whenscholarsofinternationalrelationspredictthatthe21﹩tcenturywillbeaChinesecenturytheyarefullofreasons.1AmericaremainstheonlysuperpowerChinaisresponsibleforanimportantshareofglobalchange.Since2startofthefinancialcrisisin＝2008forexampleChinahasaccounted345%ofthegaininworldGDP.In1990about＝750millionChinesepeoplelivedinextremepovertytodayfewerthan10milliondo.ItsGDPperpersonintermsofpurchasing﹣power4risetentimessince1990. China'samazing5performhasgreatlyaffectedtheworld'seconomicoutput.TheEconomisthasworkedoutageographiccenteroftheglobaleconomyby6takeanaverageofeachcountry'slatitudeandlongitude经纬度7measurebyitsGDP.AttheheightofAmerica'scontrolthispoint8previoussatinthenorthAtlantic.ButChinahaspulleditsofareast9theglobalcenterofeconomicgravity10benowinSiberia.
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同温下，电离平衡常数越小表示弱电解质电离能力越弱 多元弱酸各步电离平衡常数相互关系为：K1
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