(i)CO(g)+2H2(g)=CH3OH(g) ∆H1=-90.1 kJ·mol-1
(ii)CO(g)+H2O(g)=CO2(g)+H2(g) ∆H2=-41.1 kJ·mol-1
(iii)CO(g)+3H2(g)=CH4(g)+H2O(g) ∆H3=-206 kJ·mol-1
(iv)2CH3OH(g)=CH3OCH3(g)+H2O(g) ∆H4=-24.5 kJ·mol-1