(1)① According to the concept of combustion heat, combined with thermochemical equation, 2h2 (g)+O2 (g) = 2h2o (l) △ h =-571.6kJ/mol, and the combustion heat of hydrogen is: H2 (g)+12o3.

So the heat of combustion of hydrogen is 285.8KJ/mol, so the answer is: 285.8;

②( 1)CO(g)+2H2(g)？ CH3OH(g)△H=-90.8kJ/mol。 (2)H2 (g)+12O2 (g) =H2O (g) △ h =-241.8kj/mol;

(2)×2-( 1): CH3OH (g) +O2 (g)? CO(g)+2H2O(g)△H=-392.8 kJ/mol, so the answer is: -392.8? kJ/mol；

③ The reaction is carried out in a container with constant temperature and volume. CO (g) +2H2 (g)? Methanol (g)

A, the content of each component remains unchanged in the equilibrium state, which proves that the reaction reaches equilibrium, so A is correct;

B, the initial amount and consumption of hydrogen and carbon monoxide, the concentration of H2 in the container is equal to the concentration of CO, which cannot prove that the reaction reaches equilibrium, so B is wrong;

C, the density of mixed gas = gas mass gas volume, gas mass is conserved in the reaction process, container volume and density are unchanged, which cannot prove that the reaction reaches equilibrium, so C is wrong;

D, the ratio of chemical reaction rate is equal to the ratio of stoichiometry in the chemical equation, and the generation rate of CO is equal to the generation rate of CH3OH, indicating that the positive and negative reaction rates are the same, so D is correct;

So the answer is: ad;

(2) (1) reaction is CH3OH(g)? CO(g)+2H2(g), the reason why this reaction can proceed spontaneously is that △ H-T△ S < 0, and the reaction is an entropy-increasing reaction, so the answer is: the reaction is an entropy-increasing reaction;

② When n(O2)/n(CH3OH)=0.25, the main reaction between CH3OH and O2 is the catalytic oxidation of methanol to formaldehyde, and the reaction equation is: 2HCHO+2H2O; Heating with 2ch2 oh+O2 catalyst; According to the image analysis, it is best to control n(O2)/n(CH3OH)=0.5 when preparing H2, so the answer is: 2HCHO+2H2O is heated by 2ch2 oh+O2 catalyst; ; 0.5;

(3) Under acidic conditions, methanol on the negative electrode loses electrons to generate carbon dioxide and hydrogen ions. The electrode reaction formula is CH3OH+H2O-6e-=CO2+6H+, so the answer is ch3oh+H2O-6e-= CO2+6h+.