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OneMondaymorning,Paulandhisclassmateswereinsciencelaboratoryfortheirpracticalchemistrylesson.Thestudentsweregoingtoworkinpairstodoanexperiment.Beforetheybegan,theteachergavethemthisdescriptionofthedifferent
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更新时间:2024-04-27 00:41:26
问题描述:

OneMondaymorning,Paulandhisclassmateswereinsciencelaboratoryfortheirpracticalchemistrylesson.Thestudentsweregoingtoworkinpairstodoanexperiment.Beforetheybegan,theteachergavethemthisdescriptionofthedifferentstagesoftheexperiment.
Stage1:Preparetheequipment:atesttube,acrucible,aBunsenburnerandtongs.
Stage2:Weigh5gramsofbakingsoda(sodiumbicarbonate)andputitinacrucible.
Stage3:Heat10mlofhydrochloricacid(盐酸)inatesttube.
Stage4:Pourthewarmacidontothebakingsodaandcontinuetoheatthemixture.
Result:Theacidreactswiththebicarbonate(碳酸氢盐)toformwater,carbondioxidegasandsalt.Thehotterthemixture,thequickerthereaction.Continuetoheatthemixtureuntilthewaterevaporates,leavingthesaltinthecrucible.
Paulandhispartnerfollowedtheinstructionsandsetuptheirequipment.Paulwenttothecupboardtogetabottleofhydrochloricacid.Hefoundthattherewasonlyonebottleinthecupboardsohetookthat.TherewasnolabelonthebottleandPauldidn’tcheckwiththeteacherifitwastherightsolution.
Hemeasuredtheliquidandpoureditintoatesttube.Usingtongstoholdthetesttube,heheateditovertheBunsenburner.That’swhenthingsstartedtogowrong.Theliquidinthetesttubewasnothydrochloricacid.Whenitwasheated,itformedathickcloudofwhitegas.Soontheroomwasfullofthisstrongsmellingwhitegas.
Allthestudentsstartedcoughingandtheireyeshurt.Theteacherimmediatelyopenedthewindowsandorderedthestudentstoleavethelaboratoryatonce.Sherealizedthattheliquidwasacrylamide(丙烯酰胺)andthatitispoisonous.
Fortunately,nobodywasinjuredintheincident.However,ittaughtthestudentsandtheteacheragoodlesson.
小题1:Whatlessondidtheincidentteachthestudentsandtheteacher?

A.Neverhaveabottlewithoutalabelinthechemistrylab!
B.Obeyyourteacher’sinstructionsintheChemistrylab.
C.Acrylamidecan’ttaketheplaceofhydrochloricacid.
D.Findingsomethingunusualhappened,youhavetoleavethelaboratoryatonce.
小题2:Whatsubstancewerethestudentsmakingintheexperiment?

潘宁川回答:
  小题1:A小题2:C小题3:D小题4:C   
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