氢气(H2)、一氧化碳(CO)、辛烷(C8H18)、甲烷(CH4)的热化学方程式分别为:
H2 (g) + 1/2O2(g) ="=" H2O (l); △H = -285.8 KJ/mol
CO(g) + 1/2O2(g) ="=" CO2(g); △H = -283 KJ/mol
C8H18 (l) + 25/2O2(g) ="=" 8CO2(g) + 9H2O (l); △H = -5518 KJ/mol
CH4 (g) + 2O2(g) ="=" CO2(g) + 2H2O (l); △H = -890.3 KJ/mol
相同质量的H2、CO、C8H18、CH4完全燃烧时,放出热量最少的是
A.H2 (g) |
B.CO(g) |
C.C8H18 (l) |
D.CH4 (g) |