合成二甲醚的三步反应如下:
2H2(g) + CO(g)CH3OH(g) ΔH1
2CH3OH (g)CH3OCH3 (g) + H2O(g) ΔH2
CO(g) + H2O (g)CO2(g) + H2(g) ΔH3
则 3H2(g) + 3CO(g)CH3OCH3(g) + CO2(g) 的ΔH是
A.ΔH=2ΔH1+ΔH2+ΔH3 | B.ΔH=ΔH1+ΔH2+ΔH3 |
C.ΔH=ΔH1+2ΔH2+2ΔH3 | D.ΔH=2ΔH1+ΔH2—ΔH3 |