5.5 SOURCES OF S.J.T.U. NFORMATION ON△G Phase Transformation and Applications △H?=△H98+ACp(T-298) The difference in heat capacities △S,=A5Sw+aC,298） between reactants and products is small or if the data upon which the standard free values are not △G=△H°-TAS sufficiently precise to justify the inclusion of differences in heat capacity. SJTU Thermodynamics of Materials Spring2006©X.J.Jin Lecture 9 Chemical equilibrium IlPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © X. J. Jin Lecture 9 Chemical equilibrium II 5.5 SOURCES OF INFORMATION ON ΔG˚ )298( T 298 P TCHH −Δ+Δ=Δ D D D ) 298 ln( 298 T CSST P D D D Δ+Δ=Δ D D D T Δ−Δ=Δ STHG The difference in heat capacities between reactants and products is small or if the data upon which the standard free values are not sufficiently precise to justify the inclusion of differences in heat capacity