△H,T1 aA+bB(T) cC+dD(T) △H △H2,T2 aA+bB(T2) cC+dD (T2) ·由上图，根据Hess定律，T2下的反应焓变可由下式计算： ● △H2=△H1+△H3+△H4 ● =AH+2TaCp.(A)+bCp.m(B)]dT+ Cp(C)+dCp(D)ldT △H,=AH+iPA,CdT 定义：△.Cp=v,Cpm(d ·v:产物为正；反应物为负。• 由上图, 根据Hess定律, T2下的反应焓变可由下式计算: • H2 = H1 +H3+ H4 • = H1 +∫T2 T1[aCp,m(A)+ bCp,m(B)]dT+ ∫T1 T2[cCp,m(C)+ dCp,m(D)]dT • H2 = H1 +∫T1 T2rCpdT • 定义: rCp=∑iCp,m(i) • I : 产物为正;反应物为负. aA+bB (T2 ) aA+bB (T1 ) cC+dD (T2 ) cC+dD (T1 ) H4 H3 H2 ,T2 H1 ,T1