CH
3OCH
3(二甲醚)常用作有机合成的原料,也用作溶剂和麻醉剂。CO
2与H
2合成CH
3OCH
3涉及的相关热化学方程式如下:
Ⅰ.CO2(g)+3H2(g) CH3OH(g)+H2O(g) ΔH1=-49.1kJ·mol-1
Ⅱ.2CH3OH(g) CH3OCH3(g)+H2O(g) ΔH2=-24.5kJ·mol-1
Ⅲ.CO2(g)+H2(g) CO(g)+H2(g) ΔH3
Ⅳ.2CO2(g)+6H2(g) CH3OCH3(g)+3H2O(g) ΔH4
回答下列问题: