已知在25℃,101kPa下,lgC8H18(辛烷)燃烧生成二氧化碳和液态水时放出48.40kJ热量。表示上述反应的热化学方程式正确的是 A C8H18(1)+12.5O2(g)=8CO2(g)+9H2O(g) △H=-48.40kJ·mol-1 B C8H18(1)+12.5O2(g)=8CO2(g)+9H2O(1) △H=-5518kJ·mol-1 C C8H18(1)+12.5O2(g)=8CO2(g)+9H2O(1) △H=+5518kJ·mol-1 D C8H18(1)+12.5O2(g)=8CO2(g)+9H2O(1) △H=-48.40kJ·mol-1
答案:B