已知:CH3CH2CH2CH3(g)+6.5O2(g)===4CO2(g)+5H2O(l)正丁烷 ΔH=-2 878 kJ·mol-1(CH3)2CHCH3(g)+6.5O2(g)===4CO2(g)+5H2O(l)异丁烷 ΔH=-2 869 kJ·mol-1下列说法正确的是( )