IntroductiontoChemicalandBiologicalEngineering(CBE101)DepartmentofChemicalandBiologicalEngineering

ColoradoStateUniversity

CoursePacket

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TableofContents

ResourcesforLabGroups.................................................................................................................-4-

EssentialsforSuccessfulGroupWork..................................................................................................-6-

LaboratoryReportInstructions............................................................................................................-9-

ExampleLabReports..........................................................................................................................-11-

GroupAssessmentForm....................................................................................................................-20-

EssentialWebResourcesforCBEStudents.....................................................................................-21-

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ResourcesforLabGroups

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EssentialsforSuccessfulGroupWorkIn CBE 101 lab you have to work in groups. Some of you will thrive in this setting; others will feelfrustrated,annoyed,orperplexed.Successfulgroupworkrequiresthatconflictsbe(1)prevented,(2)identifiedand(3)resolved.Thenextthreesectionsdescribethesesteps.PreventingConflictsinGroupsIfeachmemberofyourgrouphasthesesevenexpectations,yougroupwillavoidmostconflicts.ThislistiswhatIexpectfromallofyouasindividualsandasgroups.

1. Successful groupwork requires engagement.Everyone is expected tomake contributions to the

group.Ifsomeoneisnotcontributingthegroupshouldencouragethatpersontoengage.

2. Successfulgroupworkrequirescommunication.Beveryclearwithyourgroupabouthowyouwillcommunicate, and then always respond in a timely way. If you agree to communicate by email,always reply toyourgroups’emailmessages,anddon’t leavepeopleout.Alwaysshareelectronicfilesanddatacollectedduringthelabwiththeentirelabgroupassoonaspossible.Thiswayiftheonepersonwhohasthedatalosesitorcannotattendagroupmeeting,thegroupcanstillfunction.

3. Successful group work requires planning. Everyone has different priorities and schedules. Besensitivetootherpeoples’priorities.Youreveningjobisnotmoreimportantthananotherstudent’sweekendleisureactivity.Eveningsandweekendsarejustthat–eveningsandweekends.Aslongaspeopleagreetocommitmentsandcontributionsandfollowthroughwiththem,thereshouldbenocomplaintsabouthowotherpeoplemanagetheirtime.Forthatagreementtohappen,yourgroupneedstoplanmeetings,contributions,anddeadlines.

4. Successful groupwork requires flexibility. Thingswill never go theway that you think theywill.Someone (maybe you)will notmeet a deadline. It could be that their contributionwas justwaymoredifficultandtime-consumingthananyonethoughtitwouldbe.Askforhelpwhenyouneedit,andbehelpfulwhenyoucan.Bewillingtochangeyourplansifnecessary.

5. Successfulgroupworkcanbeaccomplishedremotely.Itisokifonepersoncannotmeetwiththerest of the group. That person can still make valuable contributions by performing calculations,writingandeditingsectionsofareport,andsendingthemtotherestofthegroupbyemail.

6. Successfulgroupworkrequiresextratime.Donotexpectthateverygroupwillworkefficientlyandeffectively from the very start. Everyone has a different schedule, level of understanding of thematerial, writing ability, work temperament, personality, etc. Excellent groups spend some extratimecommunicating,planning,meeting,anddouble-checkingandeditingthecontributionsoftheirgroupmates.

7. Successfulgroupworkwillresultinabetterproductthanindividualwork.Everyoneinyourgroupshouldhavethegoalofproducingabetterreportthananyofyoucouldproduceonyourown.Youshouldexpectthatwhatyouwillwriteorcalculatewillbechecked,edited,andimprovedbyothersin your group, and that you should spend some time similarly improvingwhat theyproduce. Youshould not be offended if others editwhat youwrite, and you should not begrudge the need tospendextratimeeditingyourgroupmembers’contributions.Theseactivitiesareanessentialpartofgroupworkthatwillhelpyoubecomeabetterstudentandabetterengineer!

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IdentifyingSourcesofConflictYourgroupisalmostguaranteedtoencountersituationsthatcould leadtoconflict.Byconsideringthefollowingscenariosbefore(orduringandafter)theyoccurtoyou,yourgroupmightavoidconflict.

1. Oneormoregroupmembersaredoingallthework,whileoneorafewoftheothersaredoing

very little.Thesolution isENGAGEMENT.Thiscanhappenforavarietyofreasons,and isnotthewayasuccessfulgroupshouldfunction.Non-contributingmembersmightfeeluncertainabouttheirability,uncomfortableaskingquestions,orsimplyun-interestedinworkingwithagroup.Themoreactive members of the group can prevent conflict by communicating that they value thecontributionsofthelessactivemembers.Thiscansometimesbeaccomplishedbyaskingquestions.“Do you understand this calculation?” “How do you think we should estimate this uncertainty?”“Can you please read what I wrote and suggest some edits?” “Could you double check thesecalculations– I’mnot sure Ihave thisunit conversion right.”Failing toengageonly reinforces thebehaviorofthenon-contributingmembers.

2. One groupmember cannotmeet a deadline or join the group at an agreedmeeting time. ThesolutionisCOMMUNICATION.Thisgroupmembermightbehesitanttoadmitthattheyneedhelpcompleting something, or that they didn’t do a good job managing their time. This attitude isunderstandable–butthegroupmembershouldheeditem2inthefirstlist.Thebestwaytoavoidconflict is to tell the group exactlywhat is going on, andmake alternative arrangements. If theyremain silent, the rest of the group will likely come to the logical conclusion that the absent ordelinquentmemberdoesn’twanttocontributeor is justbeingrudeand inconsiderate.Thegroupshouldrespondbygivingdelinquentmembersthebenefitofthedoubt–offertohelp,expectthatthemembercanstill finishthework,be flexibleandwilling tore-arrangetheworkloadto includethismembertotheextentpossible.

3. Groupmembershavedifferentpriorities.ThesolutionisPLANNING.Discussingwhyagroupcan’tmeetonaparticularweekendorweeknightwillonlyleadtothegroupmakingsubjectivejudgmentsaboutwhoseactivitiesandschedulesaremoreimportant(isstudyingforanexamforanotherclass,takinganextrashiftatwork,orattendingafriend’sweddingalegitimatereasontomissameeting?Asagroup, youcannotprioritizeotherpeople’sactivities.)Asagroup, youhave toagree toplanaroundeachother’sconflictswithouttryingtomanagetheirtimeforthem.Studentsshouldalwaysbepresentduringclass,unlesstheyhaveaconflictduetoaUniversitysanctionedevent(e.g.NCAAsportsteams,etc.).Outsideofclassstudentsshouldhaveseveralhoursperweektodedicatetothisclass,butthoseparticularhoursmightnotalwayscoincide,soyouhavetoplanandbeflexible.

4. One group member has consistent rude or unhelpful behavior. The solution is COURTESY. Astudentwhoisconsistentlyun-responsivetoemails,failstomeetpreviouslyagreedobligations,orisotherwise inconsiderate of groupmemberswill cause a conflict within a group. The bestway toavoidthisistonotbethatguy!Theentiregroupneedstocommunicateaboutthisbehaviorearlysothatitdoesn’tleadtoextraworkfortherestofthegroupmembers.Theyshouldalsocommunicateconcernstotheinstructorassoonastheybecomeapparent.

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ResolvingConflictsDespiteyourbestefforts,someconflictswillarise.Whenthathappens,hereiswhatyoushoulddo:

1. Letme know that your group has a problem, and exactlywhat that problem is. This shouldbe

doneassoonastheconflictarises.Emailoravisittomyofficeisbest.

2. Suggest reasonable solutions.Your ideas abouthoweveryone should get along areprobably thebestideas(andmightbemoreagreeabletoyouthanmysolution!).

3. Erronthesideofrestoringandredeemingsuccessfulgroupwork.Youdonotabsolutelyhavetowork in a group outside of class to be successful in CBE 101. If your group absolutely cannotfunction, youmay be permitted to submit lab reports on your own – but that is rarely the bestsolution.

4. Donotallowthebehaviorofonegroupmembertocausea lotofanxietyorextraworkfortherestofthelabgroup.Recognizethatthereisaproblemandtakethestepsabovetoresolveit!

Ifyouletmeknowthatyourgrouphasaconflict,thisiswhatyoucanexpectfromme:

• Iwillwanttoknowexactlywhattheproblemisandwhatstepsyouhavetakentoresolve(orperhapscomplicate)thesituation.

• Iwilldiscusstheconflictwithallmembersofthegroup,andexpectyoutodothesame.• I will suggest a short-term course of action for the current situation. This might be a

redistributionoftheimmediateworkload,ameetingwiththeentiregroup,orthatsomegroupmembersworkseparately.

• Iwillcoachthegrouponhowtorelievethepressuresthatledtotheconflictinthefirstplace.Thisrarelyinvolvesthebehaviorofasinglegroupmember.Usually,evenifonegroupmemberis causing headaches for everyone else, the group’s responses are just as important as theoriginaloffenses.

• Groupsmight be reassigned – especially in the case of ‘no-fault’ types of conflicts – such ascompleteincompatibilityofthevariousgroupmembers’classandworkschedules.

• Iwillexpectthatyouprovidecontinuedfeedbackonhowtheconflictisbeingresolved.Anoteonleavingalabgroupmember’snameoffofalabreport:If your group has one ormoremembers who aremaking no substantial contribution to the group’swork, thentheirnameshouldnotbe includedonthe labreport.Notethat this isNOTasolutiontoaconflict–thisisasignthatthereisaproblemwithinthegroupthatneedstobeaddressed.YoushouldNOTdothis ifagroupmember isdemonstratinggenuineenthusiasmor interest incontributingbut isjustunhelpful,clumsy,orincompetent.Ifyourgroupsubmitsareportwithoneormorenamesmissing,youshouldalsodothefollowing:

1. Notifymethatyourgroupishavingaproblemandwhattheproblemis.2. Notifythedelinquentmember(oraskmetodoitforyou).Don’tsurprisethemonthedaythat

thereportisdue!3. Providethatgroupmemberwiththedatayourgrouphascollectedinthelab,especiallyifthey

participatedinthelabactivity.Theywillneedthedataiftheychoosetowriteandsubmittheirownlabreport.

4. Expectthatanypresentconflictcanberesolvedsothatthegroupcancontinuetofunctionwellonfuturework.

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LaboratoryReportInstructionsAlllabreportsshouldconformtothefollowingformat.• Use8½”×11”pagesize,single-spaced,12-pointfont,1-inchmargins,andconsistenttypeface.• Two to three pages of text is a good length for most reports. Use the length you need to

communicate everything that you need to say, without adding extra, superfluous text just to fillspace.Gradersdon’tliketoreadmorethantheyhaveto!

• Figuresandtablesshouldbeincludedasneeded,butthesedonotcounttowardtotallength.• Figures and tables should be prepared in a professional manner, preferably using engineering

software.Hand-drawnillustrationsmaybeokinsomesituations,aslongastheyarewell-prepared.Prepare figures electronically whenever possible. Physical quantities should include units anduncertainties,andonlythecorrectnumberofsignificantdigits.Seepages8-10formoreinformationonhowtocorrectlyreportsignificantdigitsanduncertainties.

• Alldisplay items(figures,tables,etc.)shouldbenumberedandhaveabriefcaption(placedbelowthe imagefor figures, includinggraphs,schemes,anddiagrams)or title (placedabove, for tables).Seeyourtextbookforexamplesofhowtocorrectlylabelfiguresandtables.Displayitemsshouldbereferredtointhetextbytheirnumber.

• Allequationsshouldbepreparedprofessionally(e.g.usingInsertàEquationinMSWord)andsetontheirownline.Defineallsymbolsused,anduseconsistentnotation.

• Include the names of all lab group members that contributed to the experiments and thepreparationofthereport.

• Everythingthatyouwriteshouldbeinyourownwords!Donotcopytextfromthelabdescriptionorothers’labreports!

See the includedexamplesofexcellentandpoor lab reports.Theentire report (includingappendices)should be prepared as a single file and submitted electronically, via Canvas. Supporting files such asMATLAB programs or Excel spreadsheetsmay also be submitted, but it is not ok to submitmultipleversionsorseveralfilescontainingdifferentsectionsofthetext!

WritingstyletipsWritingagrouplabreportisagroupeffort.Eachmemberofthegroupmakessomecontributions,andthereportmightbecompiledbyoneortwopeople.However,everymemberofthegroupshouldreadthefinalreportbeforeitissubmitted.Donotsimplycutandpastesectionswrittenbydifferentpeopletogether and expect to have a good report. Plan on spending some time editing the final version tomake it cohesive. If several people write different sections, you may need to add appropriatetransitions,movetextfromonesectiontoanother,deleteredundantorcontradictorystatements,andeditforconsistentuseofwordingandnotation.Writingasagroupshouldbeanexercisethatimproveseveryone’s finalproduct, rather thanacompilationoferrors.Donotbeoffendedifagroupmembersuggestsre-wordingordeletingsomethingthatyourwrote.Theobjectiveshouldbetoproducethebestfinalproduct.Hereisalistofadditionalthingstocheckwhenediting:• Check the spellingandgrammar.Usegood sentence structure. Eliminate run-on sentences.Make

surethatthesubjectandverbareinagreement,anduseparallelconstructionseffectively.• Usegoodparagraphstructure.Eliminatesingle-sentenceparagraphs.• Organizeideaslogicallywithinparagraphsandwithinsections.• Striveforsmoothflowofideas.Ideasshouldbeintroducedandsupported,andthetransitiontothe

nextideashouldmakesense.Useconsistentwording,notation,andvoicethroughout.• Checkthetone.Itshouldbeprofessionalbutnotstilted.• Confirmcorrectunitsandsignificantfiguresonallphysicalquantities.• Re-readthelabinstructionstobesurethatyouhaveansweredallofthequestions.

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SuggestedoutlineI. Introduction(orOverview,orObjective)

In oneor twoparagraphs, describe theobjective/goal of the experiment. Concisely describe thephysicalprincipleinvestigated.

II. MaterialsandEquipment(orExperimentalApparatus)

In one or two paragraphs, briefly describe thematerials and equipment or apparatus thatwereused.Explainanyspecialpreparationsthatwererequired.

III. Procedure(maybecombinedwiththeprevioussectionforsimpleexperiments,butforcomplex

ormulti-stepproceduresthismightbeaseparatesection)In your own words, briefly summarize the steps taken during the experiment. Provide enoughdetailsothatsomeonewhoisunfamiliarwiththeexperimentwouldunderstandwhatyoudidandwhyyoudidit.Besuretodescribeanydeparturesfromthestandardprocedure.

IV. ResultsandDiscussion

Report your results and observations. For quantitative experiments, be sure to provide the rawdata and the equationsused in your calculations, aswell as the final results. If original data areextensive,theycouldbeincludedasanappendixandreferredtointhissection.Tables,graphs,andfigures should be used effectively to highlight key findings and to summarize your results.Discuss what you concluded from the results obtained and the observations made. Explain thereason(s) for any discrepancies in your results, even if it is necessary for you tomake educatedguesses. Be sure to answer any questions posed in the lab guide for the experiment. Includediscussion of possible sources of error anduncertainty in experimentalmeasurements. Separate“Results”and“Discussion”sectionsmightbeappropriate.

V. Conclusion

Inasingleparagraph,brieflysummarizethekeyresultsandthemainpointsfromyourdiscussioninsectionIV.Thissectionmightbemissingifseparate“Results”and“Discussion”sectionsareused.Inthiscase,thelastparagraphofthe“Discussion”shouldbetheConclusion.

VI. ReferencesAlistofreferences(ifany)citedinthebodyofthereport.

VII. Appendices

Include data and notes collected during the lab, and hand-written example calculations. This isparticularlyimportanttodemonstratecorrectuseofunits.Sincetheseareyourlabnotes,itisoktocrossoutamistakeandcorrectit.Donoterase!

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ExampleLabReports

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CBE101:IntroductiontoChemicalandBiologicalEngineering

Spring2019Lab10–U-TubeManometers

Inthislaboratoryassignmentyouwillexploretheconceptofstaticfluidpressure,bymeasuringthepressure of a column of fluid. You will compare the pressures of various fluid columns to thetheoreticalpressuresthatthesecolumnsshouldgenerate.Thecolumnsof fluidwillbecreatedbyfillingareservoirwithavolumeoffluid.ThepressurewillbemeasuredusingaU-tubemanometer.Principles:Thepressuregeneratedbyacolumnoffluidatrestiscalledthehydrostaticpressure.Recallthatapressure,𝑃,canbedefinedasaforce,𝐹,actingonanarea,𝐴.

𝑃 =𝐹𝐴

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Inthecaseofthehydrostaticpressureofacolumnofliquid,theforceistheforceofgravityactingonthemassofliquid,andtheareaistheareacross-sectionofthecolumn.Theforce,𝐹,inequation1canbewrittenas: 𝐹 = 𝑔𝑚 = 𝑔𝜌ℎ𝐴 (26) Where𝑔isthegravitationalacceleration,𝜌isthefluiddensity,andℎisthedistancefromthetopofthe column to the point where the pressure is beingmeasured. Inserting the right-hand side ofequation26intoequation25yields: 𝑃 = 𝜌𝑔ℎ (27) Thus,thedifferenceinpressure,Δ𝑃 = (𝑃]–𝑃 ),betweentwoheights𝑧]and𝑧^canbewritten: Δ𝑃 = 𝜌𝑔 −Δ𝑧 (28) Manometeroperation:AU-tubemanometer is illustrated inFigure10.1.AU-shapedtubeisfilledwithafluid,andthedifferenceintheheightofthefluid on either side of the “U” is used to determine thedifference in fluid pressure on either side of the tops of thetubes.Experiments:The apparatus for this lab is illustrated in Figure 10.2. Youhavethreecylindricalgraduatedvesselsofdifferentdiameters(2,3,and5cm)andthreefluidsofdifferentdensities(water,50%2-propanol inwater, and50%sucrose inwater).Eachvessel is equipped with a mercury-containing U-tubemanometer thatmeasures the pressure at the bottom of thecolumnrelativetotheatmosphere.

𝑧^𝑧]

𝑃] 𝑃

𝑧^

𝑧]

𝑃] 𝑃

a.

b.

Figure10.1.AU-tubemanometerwith𝑃 = 𝑃](a.),andwith𝑃 < 𝑃](b.).

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Datacollectionandanalysis:Use the smallest cylinder tomeasure the pressure of threedifferentcolumnsofwaterofdifferentheights.Youmayusethe common pressure units of mmHg (millimeters ofmercury) since this is the natural pressure units for amercury-filled manometer. Verify that the apparatus isproperly calibrated. (Hint: you can use equation 28 tocalculate both the pressure of a column of liquid water ofknown height and the pressure reading of the manometer.The density of liquid mercury is 13.534 g cm-3. And thedensityofwateris1gcm-3.)Onceyouhaveverifiedthatthesmallestcylinderisproperlycalibrated, repeat the experiment with the other threecylinders. Does the diameter of the cylinder affect themeasuredpressure?Whyorwhynot?

Nowuseoneormoreofyourcylinders tomeasure thedensityof theother two liquids(50%2-propanolinwater,and50%sucroseinwater).Caution: Mercury is a hazardous material. The U-tube manometers contain mercury. While themanometersaredesignedtobesafetohandle,youshouldbecarefulnottobreakthem.Ifmercuryis accidentally released, do not touch it or attempt to clean it. Let the lab assistant knowimmediately.The lab shouldbeevacuatedand theCSUEnvironmentalHealth andServicesoffice(491-6745)shouldbenotifiedsothatproperlytrainedprofessionalscancleanupthemercuryspill.

Figure10.2.Apparatusforthislab:threegraduatedcylindersofdifferentdiameters,eachequippedwithamercury-filledU-tubemanometerthatmeasuresthepressureatthebottomofthecylinder.

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Lab10CBE103Group51ImaStudentMiaSmartsAllanA.DayAU-tubemanometerisadeviceformeasuringpressure,whichisbasedonequation28.Infact,equation28issometimesreferredtoas“themanometerequation.”Weusedamanometertomeasurethepressureofacolumnofthreedifferentliquids,usingthreedifferentcolumns.Wealsomeasuredthepressuresforvariousheightsoftheliquidstofindouthowthedensitychangeswithpressureorcolumnheight.Eachcolumnmeasuredthecorrectpressureforwatereventhoughtheyaredifferentdiameters.TheareaforacircleispD2/4.So,whenyoucomputetheareaforeachcylinder,yougetadifferentnumber.Butequation28doesn’thavetheareaorthediameterinitsoitdoesn’tmatter.Wemeasuredthedensityoftheothertwoliquids.Theyare:Propanol+water=-0.9g/cm3Sucrose+water=1.2g/cm3Thedensitiesofthemixturesaredifferentbecausepropanolisaliquid,butsucroseisasolid,sowhenyoumixthemwithwater,propanolmakestheliquiddensitygodownandsucrosemakestheliquiddensitygoup.

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Lab10,CBE101Group61(IkeNewton,JoeyGibbs,andMaryCurrie)

Hydrostaticpressuresandmanometers

ObjectiveTheobjectiveofthislabistouseU-tubemanometerstomeasurethehydrostaticpressureofcolumnsofthreedifferentfluids.Thehydrostaticpressureisthepressurecausedbytheweightofastationarycolumnofafluid.Thehydrostaticpressuredependsupontheheightofthefluidcolumnandthefluiddensityaccordingtothemanometerequation:

∆𝑃 = 𝑔𝜌 −Δ𝑧 Thisprincipleofhydrostaticpressurecanbeusedtomeasureunknownpressures,ifafluidofknowndensityisused.ThisistheprincipleofaU-tubemanometer.AU-tubemanometerisadevicethatmeasuresapressuredifferencebythechangeintheheightofacolumnofaliquidofknowndensity.Acommonfluidusedinmanometersismercury,thuspressureissometimesmeasuredin“millimetersofmercury”(mmHg),whichhasdimensionsofpressure,notlength.ApparatusandProcedureThreecolumnsofdifferentdiameterswereprovided.ThecolumnsareeachconnectedtoaU-tubemanometersothatthepressureatthebottomcanbemeasured,whenthecolumnscontainafluid.Thecolumnsarealsomarkedwithgraduationssothattheheightoftheliquidinsidethecolumncanbeeasilymeasured.Thefirststepistoensurethatthecolumnsandmanometersareproperlycalibrated.Todothis,wefilledthesmallestcolumnwithwatertothreedifferentheightsandmeasuredthehydrostaticpressureateachheight.Thenthedensityofwatercouldbecomputed.Sinceweknowthedensityofwater,ifwegotacorrectresult,weknewthatthemanometerandcylinderwereproperlycalibrated.Nextweperformedthesameprocedurewiththeothertwocylinders,toexaminehowtheresultsmightchangewhenthecylinderdiameterwaschanged.Oncewehadverifiedthatthepressurewasindependentofcylinderdiameter,weusedthesmallestcylindertomeasuretheunknowndensitiesoftwoliquidmixtures(50%2-propanolinwaterand50%sucroseinwater).Tomeasurethedensity,thepressureofaknownheightofeachfluidwasmeasured,andthemanometerequationwasre-arrangedtoobtainthedensity:

𝜌 =∆𝑃

𝑔 −Δ𝑧

Eventhoughonlyonemeasurementwasnecessarytoobtainthedensityforeachliquid,weactuallymadethreemeasurementsforeachliquidatdifferentcolumnheights.ResultsThemanometerreadingsatdifferentwaterheightsforeachofthethreecylindersareshownintable1.Acopyofourdatatablethatweusedtocollectthesedataandexamplecalculationsarealsoattached.Wenotedthatthepressurereadingscorrespondingtoeachheightwereapproximatelythesameforeachcylinder,whichmeansthatthepressuredoesnotdependonthediameterofthecylinder.Thedensityofwaterwascomputedfromtheequationaboveforeachmanometerreading.Weobtaineddensitiesforwaterverycloseto1g/cm3forallofthecalibrationexperiments,indicatingthatmanometersandcylinderswereproperlycalibrated.

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Table1.Manometerreadingsandcomputedwaterdensityforeachcylinder. SmallCylinder MediumCylinder LargeCylinder

Watercolumn

height(cm)

Manometerreading(mmHg)

Computedwaterdensity

(g/cm3)

Manometerreading(mmHg)

Computedwaterdensity

(g/cm3)

Manometerreading(mmHg)

Computedwaterdensity

(g/cm3)10 7.5 1.02 7.5 1.02 7 0.9520 14.5 0.986 15 1.02 14.5 0.98630 22 0.998 22 0.998 22 0.998

Nextwemeasuredthedensitiesoftheothertwoliquids.Forthisexperiment,weusedonlythesmallestcylinder.OurdatafortheseexperimentsareshowninTable2.OurdatasheetsandexamplecalculationsarealsoattachedTable2.Manometerreadingsandcomputeddensitiesforsolutionswithunknowndensities.

50%2-propanolinwater 50%sucroseinwaterFluid

columnheight(cm)

Manometerreading(mmHg)

Computedfluiddensity

(g/cm3)

Manometerreading(mmHg)

Computedfluiddensity

(g/cm3)10 6.5 0.884 9 1.2220 13 0.884 18 1.2230 20 0.907 27.5 1.22

DiscussionForthesecondpartoftheexperiment,thepressureshouldnotdependuponthediameterofthecylinder.Thepressureiscausedbytheweightoftheliquidcolumn.Thereismoreliquidinalargerdiametercolumn,buttheforceisalsodistributedoveralargerarea.Soincreasingthemassoftheliquidincreasesthepressure,butincreasingtheareaoverwhichtheforceisdistributeddecreasesthepressure,sothepressureinthemanometerequationdoesnotdependuponthediameterofthecylinder.(Thediametercancelsout.)Beforedoingthethirdpartoftheexperiment,wedidnotrealizethatonlyasinglemeasurementwasnecessarytodeterminethedensityofeachliquid.Weperformedthreemeasurementsforeachliquid.However,sincewehadmultiplemeasurements,wecouldcomparethemandseethatourdataforeachmeasurementwerefairlyclose.(Theerroronthedensitywas<5%.)Theerrorthatwedidobserveprobablycomesfromtryingtomeasurethepressureprecisely.Themanometerhasincrementsof1mmmarkedonit,butsomeofthemeasurementswerebetweenmmmarkingssoweestimated,forexample6.5mmHgforthe10-cmcolumnof2-propanolsolution.Themanometerequationpredictsthatthepressureshouldbealinearfunctionoftheheightofthecolumn,soweplottedthedatainTable2,toseeiftheyarestraightlineswithinterceptsof0.Thisplotisshowninfigure1,attheright.

Figure1.Pressureversusfluidcolumnheightshowingthelinearrelationshipfortwofluids.

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Wetriedtolookupthedensityofa50%2-propanolsolution,butwewerenotabletofinditfromareliablesource.Wedidfindthedensityof2-propanolinachemicalengineeringtextbook.1F1F

1Itwasreportedtobe0.785g/cm3.Ourmeasurementsindicatethatthe50%2-propanolsolutioninwaterhasadensityabouthalf-waybetweenthedensityofpure2-propanolandthedensityofpurewater(1g/cm3).ThedensityofsucrosesolutionsisreportedintheCRCHandbookofChemistryandPhysics. 2F2F

2A50%aqueoussucrosesolutionshouldhaveadensityof1.2295g/cm3,accordingtothisreference.Thus,ourmeasureddensityforthe2-propanolsolutionisreasonable,andourmeasureddensityforthesucrosesolutionisveryclosetotheacceptedvalue.Ourteamnotedthatinthislabweusedthemanometerequationtomeasurepressure(whentheheightanddensityofthefluidwereknown)andtomeasuredensity(whentheheightandthepressurewereknown).Wethoughtthatitmightalsobepossibletomeasureanunknownheightofafluid(ifthepressureanddensitywereknown).Itisapparentthatthemanometerequationandtheconceptofhydrostaticpressureareveryimportant,havingapplicationsinavarietyofchemicalandbiologicalengineeringproblems.Theycouldbeusedatthedesignstagetoensurethatavesselisdesignedtowithstandthepressurethatitwillbesubjectedtoduringoperation.Theycouldbeusedinaproductionsettingtomeasurethepressureinafluidorprocess.Andtheycouldbeusedinananalyticalsettingtomeasurethedensityofanunknownfluid.OneofourgroupmemberssuggestedthatthemanometerequationslooksalotliketheBernoulliequation,withthekineticenergytermsetto0andthewholeequationmultipliedbythedensity.SincetheBernoulliequationcomesfromthetotalenergybalance,wethinkthatthemanometerequationmightalsoberelatedtothephysicallawofconservationofenergy.Butanothergroupmemberrealizedthatthemanometerequationdoesn’thaveanyenergytermsinit.Soasagroup,wearenotsurewhethertheyarerelated.Energyisrelatedtoforces(forcexdistance)andpressures(pressurexvolume).Potentialenergyisalsorelatedtogandheight(mgz).Itdoesseemthatallofthetermsinthemanometerequationcanberelatedtoenergy.Wewillasktheinstructorwhetherthemanometerequationcanbederivedfromthetotalenergybalance.

1 R. M. Felder and R. W. Rousseau, Elementary Principles of Chemical Processes, 2nd Ed. New York: John Wiley & Sons., 1986. 2 CRC Handbook of Chemistry and Physics, 88th Edition (Internet Version), David R. Lide, ed. Boca Raton: CRC Press/Taylor and Francis, 2008. Accessed through the Colorado State University Library catalog website at http://catalog.library.colostate.edu, on Oct. 21, 2008.

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GroupAssessmentFormThisformmustbesubmittedbyeachmemberofthegroup.Evaluate eachmember of your group (including yourself in terms of how eachmember performedrelative to what the group expected of that individual in attending and participating in the lab andpreparingeditingandsubmittingtheassignments.Useascaleof0-10,where

• 0represents‘didnotmeetanyoftheexpectations’• 10represents’fullymetallexpectations’.

Membername Rating(0-10)

(me)

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EssentialWebResourcesforCBEStudents

WikipediaandGoogledonotknoweverything.Wikipedia isareliablesourceformostscienceand engineering topics. Like all texts (print or electronic) it does contain some errors andmisinformation.CBEstudentsatCSUshouldbefamiliarwiththeotherwebresourcesonthislist. The sources are trusted and some are suitable to be used as primary sources (e.g. it isappropriatetocitethemasareliablesourceinhomework,reports,orpublications).Othersaresimplyhelpfulcompilationsofusefulinformation.URLsaresubjecttochange.1.ResourcesaboutChemicalandBiologicalEngineering:

Ourdepartmentwebsite-Thedefinitivesourceforauthoritativeinformationaboutourprogramandclasses.cbe.colostate.edu/

TheAmerican InstituteofChemical Engineers - Theprofessional organizationwith

lotsofinformationforallthingsrelatedtoourprofession.www.aiche.org/

TheSociety forBiologicalEngineers -AgroupofbiologicalengineerswithinAIChE.www.aiche.org/sbe/

2.Authoritativetexts,availableelectronically throughtheCSU library’swebsite. Ifyouareoncampus,youshouldbeable toaccess these textsonyourcomputer.Alternatively,youcouldactuallyvisitthelibraryinpersonandreadarealbook!

CRCHandbookofChemistryandPhysics-Anessentialcompilationofdataimportantforanyoneworkinginthephysicalsciencesandengineering.

Perry'sChemicalEngineer'sHandbook-Thego-tosourceforaprimeronjustabout

anyfundamentaltopicinthecoresub-disciplinesofCBE.Thisbookalsocontainslotsofusefuldata.

Kirk-Othmer Encyclopedia of Chemical Technology - A relatively comprehensive

collectionofarticlesonmanychemicalengineeringtopics.TheKnovelLibrary-Averylargecollectionofwebbooksinscienceandengineering.

ManyofthesebroadcategoriesareusefulforCBE's,butthemost important isthe "Chemistry & Chemical Engineering" category. From there, browse thesubtopics to see how things are arranged. This library contains very valuablehandbooksandclassic textbooks inchemicalengineering.TheKnovel Library isupdatedwithneweditionsandnew textsas theybecomeavailable. Treasuresburiedhereinclude:

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DIPPR-DesignInstituteforPhysicalPropertiesisasourceforphysical,thermodynamicandtransportproperties.

The Merck Index - An Encyclopedia of Chemicals, Drugs, and

Biologicals.

Polymer Handbook - Physical properties and reactions of polymersandmonomers.

Properties of Gasses and Liquids - A handbook for thermodynamic

propertiesandphaseequilibriaoffluids.3. Alternatives toWikipedia - Online sources for physical properties and engineering datainclude:

NISTChemistryWebBook-Astandardreferenceforchemicalproperties.webbook.nist.gov/

IUPACGoldbook-IUPACCompendiumofChemicalTerminology.goldbook.iupac.org/

The Engineering Toolbox - Lots of standard information here. Think of this when

you'relookingforsomethingthatshouldbeanappendixinabookonyourshelf,butyouaren'tevensurewhichbookhasthatappendix.

www.engineeringtoolbox.com/