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. AST 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 S88= 0 T. SJTU Physical Chemistry of Materials Spring 2005( X.J.Jin Lecture 5 property relationPhase Transformation and Applications S. J. T. U. SJTU Physical Chemistry of Materials Spring 2005 © 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. ∫∫ =+Δ=Δ T P T P T dT TC dT TC SS 0 0 00 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. ∫ ∫ ∫ + Δ ++ Δ += 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