1.15 Equations of State (2) S.J.T.U. Phase Transformation and Applications ldeal gas its internal energy does not change with volume at constant temperature. a H=U+PV av +A恶 +V H =? =0-V+V=0 ap aH =0 av SJTU Thermodynamics of Materials Fall 2012 ©X.J.Jin Lecture 2 First Law llPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2012 © X. J. Jin Lecture 2 First Law II 1.15 Equations of State (2) Ideal gas : its internal energy does not change with volume at constant temperature.   0        V T U   ?        P T H V P V P P U P H T T T                            H U  PV V P RT P P V V U P H T T T                                     2   0    0        V V P H T   ?        V T H   0        P T H