Contents of Today S.J.T.U. Phase Transformation and Applications Review previous Solutions Thermodynamic activity Partial molar quantities Relative partial molar quantities Entropy of mixing:ideal solution Enthalpy of mixing:ideal solution Graphical representation etc. SJTU Thermodynamics of Materials Spring 2006 ©X.J.Jin Lecture 12 Solution I
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 12 Solution I Contents of Today Review previous Solutions Thermodynamic activity Partial molar quantities Relative partial molar quantities Entropy of mixing: ideal solution Enthalpy of mixing: ideal solution Graphical representation etc
Nomenclature S.J.T.U. Phase Transformation and Applications Solutions:溶液 Chemical potential:化学位（势） Thermodynamic activity:热力学活度 Ideal solution:理想溶液 Relative partial molar quantities:相对偏摩尔量 Entropy of mixing:混合熵 Graphical representation of partial molar quantities: 偏摩尔量的图示 SJTU Thermodynamics of Materials Spring 2006 ©X.J.Jin Lecture 12 Solution I
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 12 Solution I Nomenclature Solutions: 溶液 Chemical potential：化学位(势) Thermodynamic activity：热力学活度 Ideal solution：理想溶液 Relative partial molar quantities：相对偏摩尔量 Entropy of mixing：混合熵 Graphical representation of partial molar quantities： 偏摩尔量的图示
Introduction 1 S.J.T.U. Phase Transformation and Applications Chemical changes among pure components and compounds Solutions:elements or compounds dissolved in one another Many of the interesting properties of materials and many important chemical reactions take place Thermodynamics of these solutions SJTU Thermodynamics of Materials Spring 2006 ©X.J.Jin Lecture 12 Solution I
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 12 Solution I Introduction 1 Chemical changes among pure components and compounds Solutions: elements or compounds dissolved in one another Many of the interesting properties of materials and many important chemical reactions take place Thermodynamics of these solutions
Introduction 2 S.J.T.U. Phase Transformation and Applications 相变是物质由一个相向另一个相的传递过程 扩散是物质由高浓度区向低浓度区的传递过程 化学反应可以看作是物质由反应物向产物的传递过程 在传递过程中化学势将起决定作用。 在恒温恒压下， dG=∑4，dn 再由自由能判据dG≤0可得判据的另一形式（化学势判据）： ∑4，dn,≤0 在相变过程中物质i总是由化学势高的一相向转向化学势低的 一相，直到两相中的化学势相等为止。而物质在两相中存在的 化学势差△μ：是物质传递的动力。 SJTU Thermodynamics of Materials Spring 2006 ©X.J.Jin Lecture 12 Solution I
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 12 Solution I Introduction 2 在相变过程中物质i总是由化学势高的一相向转向化学势低的 一相，直到两相中的化学势相等为止。而物质在两相中存在的 化学势差 Δμ i 是物质传递的动力。 = ∑ i ii 在恒温恒压下， dG μ dn 再由自由能判据 dG≤0 可得判据的另一形式（化学势判据）： 相变是物质由一个相向另一个相的传递过程 扩散是物质由高浓度区向低浓度区的传递过程 化学反应可以看作是物质由反应物向产物的传递过程 在传递过程中化学势将起决定作用。 ∑ ≤ 0 i ii μ dn
例子 S.J.T.U. Phase Transformation and Applications 在等温等压下，两相平衡是常见的，如复相黄铜（铜一锌合 金)中o黄铜和β黄铜的平衡。设系统0、B两相相接触，在 等温等压下，若组分B(例如铜)有dn.由相进入B相，则o 相中B组分减少dng,而β相中B组分增加dng;其吉布斯函 数变化分别为： 0相 β相 dG=ug(-dnB) dGu(dna) 总的吉布斯函数变化等于 dG =dG+dG=(u-u)(dnB) SJTU Thermodynamics of Materials Spring 2006 ©X.J.Jin Lecture 12 Solution I
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 12 Solution I 例子 在等温等压下，两相平衡是常见的，如复相黄铜(铜－锌合 金)中α黄铜和β黄铜的平衡。设系统α 、β两相相接触，在 等温等压下，若组分B（例如铜）有dnB由α相进入β相，则α 相中B组分减少dnB ，而β相中B组分增加dnB ；其吉布斯函 数变化分别为: )( dG −= dnBBαα μ )( dG dnBBββ = μ 总的吉布斯函数变化等于 ))(( dGdGdG dnBBB α αββ −=+= μμ α相 β相