5.1 THERMODYNAMIC ACTIVITY (3) S.J.T.U. Phase Transformation and Applications Pure ∫B=XBfB 1 xnf S Standard state 0 Pure A Pure B XB SJTU Thermodynamics of Materials Spring2018©X.J.Jin Lecture 8 Chemical equilibriumPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2018 © X. J. Jin Lecture 8 Chemical equilibrium 5.1 THERMODYNAMIC ACTIVITY (3) P B B B f = x f   B P B B B B B f x f f f  = = Pure A Pure B xB fB 1 0 a B Pure Standard state