項(xiàng)目二：工業(yè)濃硝酸質(zhì)量分析任務(wù)三：

硝酸質(zhì)量分析硝酸含量測定原理及方法課程：工業(yè)分析中文Scenario2:QualityanalysisofindustrialconcentratednitricacidTask3:QualityanalysisofnitricacidPrinciplesandmethodsformeasuringnitricacidcontentCourse:IndustrialAnalysisEglish·工業(yè)濃硝酸產(chǎn)品標(biāo)準(zhǔn)GB/T337.1-2002《工業(yè)硝酸濃硝酸》項(xiàng)目98酸97酸硝酸質(zhì)量分?jǐn)?shù)，%≥98.097.0亞硝酸質(zhì)量分?jǐn)?shù)，%≤0.501.0硫酸質(zhì)量分?jǐn)?shù)，%≤0.080.10灼燒殘?jiān)|(zhì)量分?jǐn)?shù)，%≤0.020.02中文·ProductstandardforindustrialconcentratednitricacidGB/T337.1-2002《Industrialnitricacid

concentratednitricacid》project98acid97acidMassfractionofnitricacid，%≥98.097.0Massfractionofnitrousacid，%≤0.501.0Massfractionofsulfuricacid，%≤0.080.10Massfractionofignitionresidue，%≤0.020.02Eglish硝酸質(zhì)量分析過程

根據(jù)分析對象性質(zhì)設(shè)計(jì)分析方案準(zhǔn)備分析用儀器準(zhǔn)備分析用試劑準(zhǔn)確稱取樣品進(jìn)行分析對結(jié)果進(jìn)行評價中文Nitricacidqualityanalysisprocess:DesignananalysisplanbasedonthenatureoftheanalysisobjectPrepareanalyticalinstrumentsPrepareanalyticalreagentsAccuratelyweighthesampleandanalyzeitEvaluatetheresultsEglish一、方法原理硝酸是強(qiáng)酸，可用酸堿滴定法測定將樣品加入過量的氫氧化鈉標(biāo)準(zhǔn)滴定溶液中，用甲基橙為指示劑用硫酸標(biāo)準(zhǔn)溶液進(jìn)行返滴定。

中文一、TheprincipleofmeasurementmethodsNitricacidisastrongacidandcanbedeterminedbyacid-basetitrationAddnitricacidsampletoexcesssodiumhydroxidestandardtitrationsolution,andperformbacktitrationwithsulfuricacidstandardsolutionusingmethylorangeastheindicator.Eglish二、測定所用儀器硝酸易揮發(fā)，取樣分析時不能像稱取性質(zhì)穩(wěn)定的固體那樣直接稱量，必須借助安瓿球的幫忙。此外需滴定分析常規(guī)儀器和碘量瓶中文二、InstrumentsusedformeasurementNitricacidisvolatile,andwhensamplingandanalyzing,itcannotbedirectlyweighedlikeastablesolidsample.Ampouleballsmustbeusedtoweighnitricacid.Inaddition,conventionalinstrumentsfortitrationanalysisandiodinevolumetricflasksarerequiredAmpouleballiodinevolumetricflasksSucknitricacidsampleContainerforholdingnitricacidsamplesandtitrationEglish三、測定所用試劑

氫氧化鈉標(biāo)準(zhǔn)滴定溶液：c(NaOH)=1mol/L硫酸標(biāo)準(zhǔn)滴定溶液：(1/2H2SO4)=1mol/L甲基橙指示液：1g/LNaOH和H2SO4標(biāo)準(zhǔn)溶液濃度要準(zhǔn)確標(biāo)定中文三、Reagentsusedfordetermination

Sodiumhydroxidestandardtitrationsolution：c(NaOH)=1mol/LSulfuricacidstandardtitrationsolution：(1/2

H2SO4)=1mol/LMethylorangeindicator：1g/LAccuratedeterminationofNaOHandH2SO4standardsolutionconcentrationEglish四、檢驗(yàn)步驟將安瓿球預(yù)先稱準(zhǔn)至0.0002g，然后在火焰上微微加熱安瓿球的球泡。將安瓿球的毛細(xì)管端浸入盛有樣品的瓶中，并使冷卻，待樣品充至1.5mL-2.0mL時，取出安瓿球。用濾紙仔細(xì)擦凈毛細(xì)管端，在火焰上使毛細(xì)管端封閉，不使玻璃損失。稱量含有樣品的安瓿球，稱準(zhǔn)至0.0002g，并根據(jù)差值計(jì)算樣品質(zhì)量。中文四、Inspectionsteps

First,accuratelyweighthemassoftheampouleball,andthenslightlyheatthebulboftheampouleballonaflame.Immersethecapillaryendoftheampouleballintothebottlecontainingthesampleandletitcool.Whenthesampleisfilledto1.5mL-2.0mL,removetheampouleball.Carefullywipethecapillaryendwithfilterpaperandsealitontheflametopreventglassloss.

Weightheampoulecontainingthesampleandcalculatethesamplemassbasedonthedifferencebetweenthetwomasses.Eglish

將盛有樣品的安瓿球，小心至于預(yù)先盛有100mL水和用移液管移入50mL氫氧化鈉滴定溶液的錐形瓶中，塞緊磨口塞。然后劇烈震蕩，使安瓿瓶破裂，并冷卻至室溫，搖動錐形瓶，直至酸霧全部吸收為止。

取下塞子，用水洗滌，洗液收集于同一錐形瓶內(nèi)。加1-2滴甲基橙指示劑溶液，然后用硫酸標(biāo)準(zhǔn)滴定溶液將過量的氫氧化鈉標(biāo)準(zhǔn)滴定溶液滴定至溶液呈橙色為終點(diǎn)。中文

Carefullyplacetheampouleballcontainingthesampleintoaconicalflaskprefilledwith100mLofwaterandpipette50mLofsodiumhydroxidetitrationsolution,andtightenthegroundstopper.Thenshakevigorouslytobreaktheampoule,continueshakingtheconicalflaskuntiltheacidmistiscompletelyabsorbed.

Removethestopper,washwithwater,andcollectthewashingsolutioninthesameconicalflask.Add1-2dropsofmethylorangeindicatorsolution,thentitratetheexcesssodiumhydroxidestandardtitrationsolutionwithsulfuricacidstandardtitrationsolutionuntilthesolutionturnsorangeastheendpoint.Eglish五、分析結(jié)果的表述w=(c1V1-c2V2)M/m-1.34w2-1.29w3中文五、Expressionofanalysisresultsw=(c1V1-c2V2)M/m-1.34w2-1.29w3Intheformula:C1-actualconcentrationofsodiumhydroxidestandardtitrationsolution,mol/LC2-actualconcentrationofsulfuricacidstandardtitrationsolution,mol/L;V1-thevolumeofsodiumhydroxidestandardtitrationsolutionadded,mL;V2-Volumeofsulfuricacidstandardtitrationsolutionconsumedfortitration,mL;m-

themassofthesample,g;M-

themolarmassofnitricacid,ingramspermole(g/mol)(M=63.02);w2-

themassfractionofnitrousacid;w3-themassfractionofsulfuricacid;1,34-thecoefficientforconvertingnitritetonitricacid;1.29-thecoefficientforconvertingsulfuricacidtonitricacid.Eglish六、分析結(jié)果誤差分析1、安瓿球外壁沒擦干或熔封不完全2、有酸霧從碘量瓶逸出3、使用NaOH和H2SO4兩個標(biāo)準(zhǔn)溶液，標(biāo)準(zhǔn)溶液濃度誤差會引起硝酸測定誤差中文六、Erroranalysisofanalysisresults1、Theouterwalloftheampouleballisnotwipeddryorthemeltingsealisincomplete2、Acidmistescapingfromiodinevolumetricflask3、TheconcentrationerrorofstandardsolutioncancauseerrorsinnitricaciddeterminationEglish思考題1.

硝酸試樣為什么要用安瓿球取樣？2.

振蕩碘量瓶時酸霧未消失，打開瓶塞對分析結(jié)果有何影響？3.用甲基橙做指示劑，滴到顏色為黃色和橙紅色對分析結(jié)果有何影響？中文Reflectionquestions1.Whydonitricacidsamplesneedtobeweighedinampoules?2.Whatistheimpactofopeningthebottlecaponthe