物理化學(xué)偏摩爾量培訓(xùn)課件

物理化學(xué)(Ⅰ)PHYSICALCHEMISTRY

（9）過程方向和限度判據(jù)：孤立系統(tǒng)DS，熵增加原理封閉系統(tǒng)DS，熵增加原理絕熱過程DA，赫姆霍茲函數(shù)減小原 理等溫?zé)o功（等V,W’=0）DG，吉布斯函數(shù)減小原理等溫等壓W’＝0？（有物質(zhì)交換發(fā)生）開放系統(tǒng)DS，考慮環(huán)境、構(gòu)建孤立系其它過程

第三章溶液熱力學(xué)基礎(chǔ)ThermodynamicsofMulti-componentSystems(SolutionChemistry)3.1Partialmolarquantities(偏摩爾量)Characteristicsofmulti-componentand

heterogeneoussystems(1)Compositionandtheamountsofsubstancesarechangeableinsystemsinvolvingphasetransitionsandchemicalreactions.

(對(duì)其中的一相而言,可看作開放系統(tǒng))(3)Morethan3independentvariablesareneededtodefinethestateofasystem.2.PartialmolarquantitiesTakingvolumeasanexample.Forasystematthermalandmechanicalequilibrium,wehaveDefine:aspartialmolarvolumeofsubstanceB

PartialmolarinternalenergyPartialmolarenthalpyPartialmolarentropyPartialmolarvolumesofH2OandCH3CH2OHat25oCDiscussion:①Partialmolarquantitiesareintensivepropertiesofasystem.（強(qiáng)度性質(zhì)）②PerspectivesofphysicalsignificanceVxBnBChangingrateofVagainstnBatagivenstate(T,p,andconcentrationxB).

偏摩爾體積也可看作是在等溫等壓的條件下，在無限大的系統(tǒng)中加入1molB所引起系統(tǒng)體積的變化量。③Conditions:ConstantTandp.④Foramono-componentsystem,3.Twoimportantequationsofpartialmolarquantities(1)Additivityofpartialmolarproperties(偏摩爾量的集合公式，或加和公式)在指定T，p

均不變的條件下V是nB的一次齊函數(shù)。根據(jù)齊函數(shù)的Euler定理即：(2)Gibbs-DuhemequationAtconstantTandp,FromBycomparison,wehaveForbinarysystems,(A+B),VA是nA的零次齊函數(shù)，根據(jù)齊函數(shù)的Euler定理Or,Problem：集合公式和Gibbs-Duhem方程的適用條件相同嗎？Similarly,Wemayalsohave,4.Determinationofpartialmolarquantities(1)切線法(2)解析法如能從實(shí)驗(yàn)或理論得到方程(3)截距法定義:可以證明:VAVBVmxB013.2Chemicalpotentialandfundamentalequationsofthermodynamicsforopensystem1.ChemicalpotentialDefine:aschemicalpotentialofcomponentBForclosedsystem,dnB=0Set:

Define:

FundamentalEquationsofChemicalThermodynamicsforOpenSystems(開放系統(tǒng)的熱力學(xué)基本關(guān)系式)Atagivenstate,Discussion:

①μB是強(qiáng)度性質(zhì),μB=f(T,p,xB,…)②適用條件:處于熱平衡和力平衡的,沒有非體積功的均相系統(tǒng)AssignmentsReview(XCFu):4.1～4.3FurtherReadi