沼气是一种能源,它的主要成分是CH4。0.5 mol CH4完全燃烧生成CO2和液态水时放出445kJ的热量,则下列热化学方程式中正确的是
A.2CH4(g)+4O2(g)====2CO2(g)+4H2O(1);△H=+890kJ/mol |
B.CH4(g)+2O2(g)====CO2(g)+2 H2O(l);△H=+890kJ/mol |
C.CH4(g)+2O2(g)====CO2(g)+2H2O(1);△H=-890kJ/mol |
D.1/2 CH4(g)+2O2(g)====1/2CO2(g)+H2O(1);△H=-890kJ/mol |