已知101kPa时的辛烷的燃烧热为5518kJ/mol,强酸与强碱在稀溶液中发生反应时的中和热为57.3kJ/mol,则下列热化学方程式书写正确的是( )
①C8H18(l)+ 25/2O2(g)= 8CO2(g)+ 9H2O(l); △H= +5518kJ/mol
②C8H18(l)+ 25/2O2(g)= 8CO2(g)+ 9H2O(l); △H= -5518kJ/mol
③H+(aq)+ OH-(aq)= H2O(l); △H= -57.3kJ/mol
④1/2H2SO4(aq) + NaOH(aq) =1/2Na2SO4(aq) + H2O(l); △H= +57.3kJ/mol