H2(g)+1/2O2(g)=H2O(g);△H1=akj/mol 放热反应△H1<0H2(g)+1/2O2(g)=H2O(l));△H2=cKj/mol 放热反应△H2<0H2O(g)=H2O(l);△H3<0△H1+△H3=△H2 可得a以上回答你满意么?