化学专业英语部分原文及翻译　

《化学专业英语部分原文及翻译　》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、U27Theacid-basetitrationstartswiththedissolutionofthesolidacidsampleindeionizedwater.Addtheend-pointindicator,whichisphenolphthalein,withtwodropstoeachflaskcontainingtheacidsampleanddeionizedwater.Properlylabeltheflasks.Beconsistentinallofthesampleswhenad

2、dingtheindicator.Swirltheflasksuntilthesolidacidiscompletelydissolved.Finally,rinsewithdeionizedwaterthreetimesaround,whichiscriticaltoensurethatallsolidacidhasbeenremovedfromtheflaskwallsanddissolvedinthesolution.Allsolidparticlesmustbedissolvedpriortoth

3、etitration.7、酸碱滴定伴随着于固体酸溶解于去离子水屮发生。在每支装有酸样品和去离子水的试管屮加入两滴终点指示剂一一酚酞，并在试管上贴好标签。在加指示剂的时候保持所有样品条件一致。霞荡试管直到所有固体酸完全溶解。最后，用去离子水冲洗试管壁周围三次，确保试管壁上的固体酸从试管上脱落并洛解于溶液屮。所有的固体酸都必须在滴定前完全溶解。8Theburetneedstobecheckedforifitisquantitativelyclean,bothtoavoidcontaminationandtob

4、esurethattitrantvolumesareaccuratelyread.Makesuretheburetstopcockisclosed.Filltheburetwithwaterandthendrainittochecktheburet,makingsurethatitswallsdraincleanly.Beforecheckingfordrainage,waitaminuteortwoaftercompletelydrainingtheburet.Sometimesdropletsappe

5、arontheinnerwallsoftheburetaftersometime,indicatingthattheburetisnotquantitativelyclean.Inthiscase,itisnecessarytousestandardcleaningprocedurestocleantheburet.Iftheburetisdropletfree,thenitisquandtativelycleanandcanbeusedfortitration.8.滴定管需要检查，如果它是定量清洁，既避

6、免了污染又能确保滴定剂卷的准确地阅渎。确保关闭滴定管活塞。在滴定管A装满水然后排出检查滴定管，确保其壁上的水排干净。在检查排水时，等待一至两分钟后滴定管完全排千。有时滴定管内壁出现小水滴一段时间，表明滴定管不是定量清洁。在这种情况下，必须用标准的清洁程序清洁滴定管。如果滴定管是液滴自由，那么它是定量清洁和可用于滴定。10Titrantcanthenbefilledinthewell-rinsedburet.Stilluseafunneltoaddtitranttotheburet.Carefullylif

7、tthefunnelforsmoothdeliveryandtoavoidoverfillingofthetitrant.Similartothecleaningoftheburet,analternativeistoremovetheburetfromtheburetholder,anddirectlypourthetitrantfromthetitrantbottle.Letsometitrantrunthroughtheburettipintothewastecontainerandcheckwhe

8、therthereareanyairbubblesinthetip.Thebubbleswillcausedifficultyinobtainingaccuratevaluesofvolumeiftheyarenotremoved.Thebubblescanbeshakenoutbyopeningthestopcock,firmlyholdingtheburetwithbothhands,andjerkingdownwarda