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1、5.1聯(lián)氨濃度的測(cè)定Determinationof?theconcentrationof?hydrazine5.2.1試劑:Reagenta)0.1mol/LNa2S2O3標(biāo)準(zhǔn)溶液;0.1mol/LNa2S2O3standardsolutionb)0.05mol/L碘標(biāo)準(zhǔn)溶液;0.05mol/Lstandardsolutionofiodinec)1%淀粉指示劑;1%starchindicator2mol/LNaOH溶液;2mol/LNaOHsolution1mol/L(1/2H2SO4)溶液。1mol/L(1/2H2SO4)soluti

2、on5.2.2測(cè)定方法:取二只250mL具磨口塞的三角瓶，一只加入待測(cè)試樣10mL，并用除鹽水稀釋至100mL，另一只加入除鹽水100mL，各加2mol/LNaOH溶液2mL用滴定管精確加入10mL0.05mol/LI2標(biāo)準(zhǔn)溶液,充分混勻,置于暗處3min,分別加入1mol/L(1/2H2SO4)5mL,用0.1mol/LNa2S2O3標(biāo)準(zhǔn)溶液滴定過(guò)剩的I2在接近終點(diǎn)時(shí)(滴定至溶液呈淺黃色)加入1mL淀粉指示劑,繼續(xù)滴定至藍(lán)色消失,記錄Na2S2O3的消耗量。聯(lián)氨濃度按式(C27)計(jì)算：（27）式中：CN2H4—測(cè)定的N2H4濃度，mg

3、/L；a--試驗(yàn)中所消耗的0.1mol/LNa2S2O3標(biāo)準(zhǔn)溶液體積,mL;b--滴定水樣空白時(shí)消耗的0.1mol/LNa2S2O3的體積,mL;V—所取試樣的體積數(shù)mL;8—N2H4的摩爾質(zhì)量。Determinationprocess:takingtwo250mlconicalflaskwithfrostedcork,oneadd10mlsamplestobetest,andthendiluteto100mlusingdeminwater,anotheroneadd100mldeminwater,eachofthemadd2mol/l

4、NaOHsolution2ml,exactlyadd10ml0.05mol/lI2usingburette,thoroughlymixed,3minuteinthedark,respectivelyadd1mol/L(1/2H2SO4)5mL,using0.1mol/LNa2S2O3standardsolutiontitrateexcessI2whenclosedtothefinishedline(titrateuntilthesolutionchangedyellow)add1mlstarchsolutionindicator,con

5、tinuetitratinguntilthebulelost,notetheconsumptionofNa2S2O3.Hydrazine?concentration?accordingtoequation(C27)to?calculate:（27）Intheequation:CN2H4—themeasuredconcentrationofN2H4a—thevalumeofconsumptionof0.1mol/LNa2S2O3standardsolutioninthetestb—theconsumptionof0.1mol/LNa2S2

6、O3intitratingtheblanksampleV—volumeofthesample8—molecularweightofN2H41%淀粉指示劑配置稱取可溶性淀粉1g,置于瑪瑙研缽中,加少量除鹽水研磨成糊狀物,徐徐加入到100mL煮沸的除鹽水中,繼續(xù)煮沸1min,冷卻后備用。該試劑不宜存放,應(yīng)在使用時(shí)配制。Configurationof?1%?starchindicator:Weigh1gsolublestarch,andputintoagatemortar,plusasomeamountofdeminwaterandgrind

7、intoamash,Slowly?addedto?100mL?ofboiling?deminwater.continuetoboiloneminute,tobesparedaftercooling.Theagentshouldnotbestored,pleaseconfigurationbeforeusing.