SPRINGER BRIEFS IN PHYSICS Ulf W. Gedde Essential Classical Thermodynamics 123 SpringerBriefs in Physics SeriesEditors BalasubramanianAnanthanarayan,CentreforHighEnergyPhysics,IndianInstitute ofScience,Bangalore,India EgorBabaev,PhysicsDepartment,UniversityofMassachusettsAmherst,Amherst, MA,USA MalcolmBremer,HHWillsPhysicsLaboratory,UniversityofBristol,Bristol,UK Xavier Calmet, Department of Physics and Astronomy, University of Sussex, Brighton,UK FrancescaDiLodovico,DepartmentofPhysics,QueenMaryUniversityofLondon, London,UK Pablo D. Esquinazi, Institute for Experimental Physics II, University of Leipzig, Leipzig,Germany MaartenHoogerland,UniversityofAuckland,Auckland,NewZealand Eric Le Ru, School of Chemical and Physical Sciences, Victoria University of Wellington,Kelburn,Wellington,NewZealand DarioNarducci,UniversityofMilano-Bicocca,Milan,Italy JamesOverduin,TowsonUniversity,Towson,MD,USA VesselinPetkov,Montreal,QC,Canada StefanTheisen,Max-Planck-InstitutfürGravitationsphysik,Golm,Germany Charles H.-T. Wang, Department of Physics, The University of Aberdeen, Aberdeen,UK JamesD.Wells,PhysicsDepartment,UniversityofMichigan,AnnArbor,MI,USA Andrew Whitaker, Department of Physics and Astronomy, Queen’s University Belfast,Belfast,UK SpringerBriefsinPhysicsareaseriesofslimhigh-qualitypublicationsencompassing the entire spectrum of physics. Manuscripts for SpringerBriefs in Physics will be evaluated by Springerand by members of the Editorial Board. 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Gedde Essential Classical Thermodynamics UlfW.Gedde FibreandPolymerTechnology SchoolofEngineeringSciencesinChemistry BiotechnologyandHealth KTHRoyalInstituteofTechnology Stockholm,Sweden ISSN2191-5423 ISSN2191-5431 (electronic) SpringerBriefsinPhysics ISBN978-3-030-38284-1 ISBN978-3-030-38285-8 (eBook) https://doi.org/10.1007/978-3-030-38285-8 ©TheAuthor(s),underexclusivelicensetoSpringerNatureSwitzerlandAG2020 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartofthe materialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped. 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ThisSpringerimprintispublishedbytheregisteredcompanySpringerNatureSwitzerlandAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Preface Even before writing our recent book Fundamental Polymer Science (Springer Nature (2019)), I realized that a thorough understanding of thermodynamics is essential if the reader is to be able to capture the content of this specialized field. At this stage, the plan was to prepare a brief account as a supplementary chapter. When the polymer science book was delivered, however, in order to reach the broadestpossible audienceforaconciseandhighlyreadableprimeronthermody- namics, David Packer of Springer Nature proposed that I should write a separate book to be included in a series of publications called Springer Brief. At this stage, I also realized that many other books in chemistry, physics, materials science and engineeringhadthesame“problem”;aknowledgeaboutbasicclassicalthermody- namicsisrequiredinordertobeabletoabsorbthematerialinthesetexts.Thereare many comprehensive books on thermodynamics. Most of them are 500 pages or longer,and they also havea broader perspective, including kinetics, basic physics, applied thermodynamics, etc. Concise texts on classical thermodynamics are few, and many of them are quite old. These short texts are very useful for newcomers, typically first or second year university students, as a complement to the more comprehensive books. Ph.D. students, postdocs and engineers in industry and research institutes have had their basic thermodynamics training 5–10 years back, and it is possible that some of the thermodynamics is forgotten. This book is essentially aimed at this group. For the last decade, I have been teaching the thermodynamics course at KTH Royal Institute of Technology in Stockholm for students in chemistry and biosciences. This 10-year effort has taught me the prob- lemswithunderstandingthermodynamics.Ourgraduationhasincreasedbyafactor of3duringthisperiodsimplybyaddressingtheseissuesandprovidingsecond-and third-level opportunities during the course. The lesson is that inspiration, concern and time make most students knowledgeable. I feel relaxed and happy now in delivering this text to hopefully many readers. Feel free to mail me if you have questionsandideasconcerningthebook. v vi Preface Thisbookhasveryfewreferences.Itfocusestoprovideonlytheessentialsforthe understandingofthesubject.Ihaveincludedquiteafewequationsandderivations ofimportantexpressions(laws).Thesteptoapplytheformulaetoyourproblemsis notsofar-reaching. ProfessorsMikaelHedenqvist,EricTyrodeandFritjofNilsson,allatKTHRoyal Institute of Technology, Stockholm, Sweden, have provided feedback on the text. Dr. Anthony Bristow has corrected the English. Bristow is a person with a unique combinationofsenseoflanguageandfactualknowledgeofscience.DavidPackerof Springer Nature has provided inspiration and great ideas concerning this book and therecentpolymersciencebooks.Thankyou,David. Stockholm,Sweden UlfW.Gedde October7,2019 Contents 1 AnIntroductiontoThermodynamicsandtheFirstLaw. . . . . . . . . 1 2 TheSecondandThirdLaws. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3 GibbsandHelmholtzFreeEnergies. . . . . . . . . . . . . . . . . . . . . . . . 21 4 AComprehensiveViewoftheStateFunctionsIncluding MaxwellRelations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5 ChemicalPotentialandPartialMolarProperties. . . . . . . . . . . . . . 29 6 One-ComponentSystems:TransitionsandPhaseDiagrams. . . . . . 35 7 Solutions,Phase-SeparatedSystems,ColligativeProperties andPhaseDiagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 8 ChemicalEquilibrium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 9 ThermodynamicsProblems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Gases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 FirstLaw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 FirstandSecondLawsCombined. . . . . . . . . . . . . . . . . . . . . . . . . . . 76 GibbsandHelmholtzFreeEnergiesandtheMaxwellRelations. . . . . . 76 ChemicalPotentialandPhaseEquilibria. . . . . . . . . . . . . . . . . . . . . . . 76 ColligativeProperties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 ChemicalEquilibrium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 PhaseDiagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 10 SolutionstoProblems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 11 MathematicsUsefulfortheThermodynamics. . . . . . . . . . . . . . . . . 93 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 vii Chapter 1 An Introduction to Thermodynamics and the First Law Classical thermodynamics is based on several robustly formulated statements, referred to as the laws of thermodynamics. The words of Albert Einstein say something important about thermodynamics: “A theory is the more impressive the greater the simplicity of its premises, the more varied the kinds of things that it relates and the more extended the area of its applicability. Therefore, classical thermodynamics has made a deep impression on me. Thermodynamics is the only science about which I am fairly convinced that, within the framework of the applicabilityofitsbasicprinciples,itwillneverbeoverthrown”.Anotherrespected scientist,ArnoldSommerfeld,wrote:“Thermodynamicsisafunnysubject.Thefirst timeyougothroughthesubject,youdonotunderstanditatall.Thesecondtime,you thinkyouunderstandit,exceptforoneortwosmallpoints.Thethirdtime,youknow thatyoudonotunderstandit,butyouaresousedtothesubjectthatitdoesnotbother youanymore”. The history of the establishment of the first law of thermodynamics involved personsstudyingandthinkingaboutenergyovera60-yearperiod.Severalimportant experimentswerecarriedoutattheendoftheeighteenthcenturyandthefirsthalfof the nineteenth century, the most prominent being made by the British American- bornBenjaminThompson,theBritishHumphryDavy,theGermannaturalscientist Julius Robert Mayer and the brilliant experimentalist James Prescott Joule (England). Mayer, working at the time as a doctor on a ship sailing around the world, noticedtheunusual colourofvenous bloodofshipmen whenstaying inthe warmequatorialpartsoftheworld.Thisobservationstartedhisobsessioninthinking aboutenergy,workandheat.Itledultimatelytoascientificpaperpublishedin1842, in which the first law of thermodynamics was formulated as an idea. It was Joule who produced the precise experimental evidence, which really established the first law.Joulepublishedhisfindingsin1843(firstinapreliminaryform),in1847(the paper was rejected after submission) andfinallyin1849. Thisimportantpaper had the title “On the mechanical equivalent of heat”. The first law expressed in mathe- matical terms was delivered in slightly different forms by several scientists, ©TheAuthor(s),underexclusivelicensetoSpringerNatureSwitzerlandAG2020 1 U.W.Gedde,EssentialClassicalThermodynamics,SpringerBriefsinPhysics, https://doi.org/10.1007/978-3-030-38285-8_1 2 1 AnIntroductiontoThermodynamicsandtheFirstLaw Heat (q) + work (w) Heat (q) + work (w) Heat (q) + work (w) Matter (mDn) Matter (mDn) Matter (mDn) Open system Closed system Isolated system Fig.1.1 Schematicrepresentationofthreedifferentthermodynamicsystems Hermann von Helmholtz (1847), Rudolf Clausius (1850) and William Rankine (1850). The first law states that energy cannot be produced; it can only be transformed from one form to another or, differently formulated, transferred from or to the surroundingsof a given system (Fig. 1.1). The energy of the universe, whichis an isolated system, is constant. Outside the universe nothing exists, and there can thereforebenotransferofenergytoandfromtheuniverse. Figure1.1showsthreedifferenttypesofsystem: (cid:129) Anopensystem(likethebodyofalivinghuman)canexchangeheat(q),work(w) andmatter(μΔn)withitssurroundings. (cid:129) A closed system cannot exchange matter but certainly heat and work with the surroundings.Anexampleofaclosedsystemisatightmetalcontainer. (cid:129) Anisolatedsystemcannotexchangeenergyinanyofthethreetransferforms.As already noted, an example is the universe. A perfect thermos flask is another example. Thefollowingequationsaremathematicalformulationsofthefirstlaw.Equation (1.1)describesanopensystem,Eq.(1.2)aclosedsystemandEq.(1.3)theconstant internalenergyofanisolatedsystem,e.g.theuniverse: dU ¼dqþdwþμdn;ΔU ¼qþwþμΔn ð1:1Þ dU ¼dqþdw;ΔU ¼qþw ð1:2Þ dU ¼0;ΔU ¼0 ð1:3Þ wheredUisthetotaldifferentialoftheinternalenergy(unit:joule,J),dqanddware thedifferentialquantitiesofrespectivelyheatandwork(unitofboth:joule,J),μis the chemical potential (unit: joule per mole, J mol(cid:2)1) and dn is the differential change in the number of moles of matter. An alternative way of describing these