2.10 Entropy change in chemical reactions and the third law(2) S.J.T.U. Phase Transformation and Applications The third law provides a great simplification in the calculation of entropies of reaction A=as+fn号m The entropy changes near room temperature are often needed in thermodynamic calculations, the integral in above equation has been evaluated for many substance at 298 K. 298 SJTU Thermodynamics of Materials Fall 2018 ©X.J.Jin Lecture 5 property relationPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2018 © X. J. Jin Lecture 5 property relation 2.10 Entropy change in chemical reactions and the third law (2) The third law provides a great simplification in the calculation of entropies of reaction.    =  + = T P T P T dT T C dT T C S S 0 0 0 0 0 The entropy changes near room temperature are often needed in thermodynamic calculations, the integral in above equation has been evaluated for many substance at 298 K.    +  + +  = + 298 0 0 298 b b m m T P T T b P b m m T P dT T C T H dT T C T H dT T C S