上海交通大学：《材料热力学》教学资源_2010课件_lecture 5 property relation I

Contents of Today S.J.T.U. Phase Transformation and Applications Review previous Second law Functions F and G Property relation Property relation derived from U,H,F,and G etc. SJTU Physical Chemistry of Materials Spring2010©X.J.Jin Lecture 5 property relation I

Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2010 © X. J. Jin Lecture 5 property relation I Contents of Today Review previous Second law Functions F and G Property relation Property relation derived from U, H, F, and G etc

1.6 The Closed System S.J.T.U. Phase Transformation and Applications 1st Law:for a closed system Conservation of energy 8&Q+δW=dLU Nuclear reaction? Q and W are not state functions U is a point or state function 8O+W=dU+d(PE)+d(KE) PE:potential energy KE:kinetic energy Usefulness:one of the terms is unknown SJTU Physical Chemistry of Materials Spring2010©X.J.Jin Lecture 5 property relation I

Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2010 © X. J. Jin Lecture 5 property relation I 1.6 The Closed System 1 st Law: for a closed system QW  dU Q and W are not state functions U is a point or state function QW  dU  d(PE)  d(KE) PE: potential energy KE: kinetic energy Usefulness: one of the terms is unknown Conservation of energy Nuclear reaction?

1.10 Enthalpy S.J.T.U. Phase Transformation and Applications Enthalpy:defined as U+PV Relative value! (H,)mn,-(H。)n。+2+oW=dU System boundary δm SJTU Physical Chemistry of Materials Spring2010©X.J.Jin Lecture 5 property relation I

Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2010 © X. J. Jin Lecture 5 property relation I 1.10 Enthalpy (Hi )mi (Ho )mo QW  dU Enthalpy: defined as U + PV System boundary P mi mo Relative value!

1.15 Equations of State (1) S.J.T.U. Phase Transformation and Applications Equations of state the relationship among the physical variables that describe the condition of a material. For gases the relationship between pressure(P),volume (V), temperature (T)and number of moles(n). PV=ART PV-RT R:the universal gas constant:8.314 J/(mol.K) One mole of gas at 273.15 K and one atmosphere V=22.4L/mol 状态方程 理想气体的状态方程 SJTU Physical Chemistry of Materials Spring 2010 ©X.J.Jin Lecture 5 property relation I

Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2010 © X. J. Jin Lecture 5 property relation I 1.15 Equations of State (1) Equations of state : the relationship among the physical variables that describe the condition of a material. For gases : the relationship between pressure (P), volume (V), temperature (T) and number of moles (n). PV  nRT PV  RT R : the universal gas constant: 8.314 J/(molK). V  22.4L/ mol One mole of gas at 273.15 K and one atmosphere 状态方程 理想气体的状态方程

1.17 Adiabatic Compression or Expansion (3) S.J.T.U. Phase Transformation and Applications g For reversible,adiabatic process in an ideal gas 27 、2} TP %=const const PVY const 绝热压缩和膨胀 SJTU Physical Chemistry of Materials Spring 2010 ©X.J.Jin Lecture 5 property relation I

Phase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2010 © X. J. Jin Lecture 5 property relation I 1.17 Adiabatic Compression or Expansion (3) T dT R C P dP P  ( ) CP R P P T T ( ) 1 2 1 2  For reversible, adiabatic process in an ideal gas TP const CP R     TP  const   1  PV  const  V P C C   绝热压缩和膨胀