1、1.3.1 Molar enthalpies and internal energies of chemical changeaA + bB = yY + zZ1.3 Thermochemistry 1.3.2 Standard enthalpy changesStandard molar enthalpies of the substance B at temperature T and pressure p。(B=A, B, Y, Z; =phase state)1.3.3 Standard states of substances Standard pressure p100kPagas

2、:p = p , T, perfect gassolid or liquid : pex = p , T rHm (T) = yHm (Y, , T )z Hm (Z, , T ) a Hm (A, , T )b Hm (B, , T ) For reaction aA b B yY zZPure, unmixed reactant in their standard states Pure, separated products in their standard states 1.3.4 Relation between rHm and rUm For a reactionrH m (T,

3、 liquid or solid) rU m (T, l or s)rHm ( T)rUm (T)RT B (g)rH m (T) BH m (B, , T ) BU m (B, ,T ) Bp V m (B,T)T= Constant V=constant W0 QVrUT= Constant p=constant W0 QprH1.3.5 Hesss lawACBrHm (T ) = rHm,1 (T )rHm,2 (T ) The standard enthalpy of overall reaction is the sum of the standard enthalpies of

4、the individual reactions into which a reaction may be divided.rHm (T) in term of fHm (B, ,T ) r Hm (T) = Bf Hm (B, ,T )reactantselementsproductsr HmEnthalpy, H1.3.6 Standard enthalpies of formation fHm (B, ,T ) rHm (T)in term of cHm(B, ,T ) r Hm (T) = BcHm (B, ,T ) *reactantsCO2(g), H2O(l)productsr HmEnthalpy, H1.3.7 Standard molar enthalpies of combustion cHm (B,phase state ,T )1.3.8 The temperature dependence of reaction enthalpiesaA+bByY+zZaA+bByY+zZr H m (T1) = H 1 H 2 r H m (T2)H 3 H 4B Cp,