The standard of reaction is +2.85 kJ.

We can use the standard enthalpies of formation of the reactants and products to calculate the standard enthalpy of reaction.

I list their values below the corresponding formulas.

Note that the substances must be in their most stable states at 298 K and 1 bar, so water is listed as a liquid.

##color(white)(XXXXXXXXX)”CO”(“g”)color(white)(l) +color(white)(l) “H”_2″O”(“l”) →”CO”_2(“g”) +”H”_2(“g”)## ##ΔH_f^°(“kJ/mol”)color(white)(X) “-110.53″color(white)(XX) “-285.83″color(white)(XXl) “-393.51″color(white)(l)color(white)(XX)0##

##ΔH_”reaction”^° = sum(ΔH_f^°(“products”)) – sum(ΔH_f^°(“reactants”)) =” [1(-393.51) + 1(0) – 1(-110.53) – 1(-285.83)] kJ” =”2.85 kJ”##

The standard of reaction is +2.85 kJ.

We can use the standard enthalpies of formation of the reactants and products to calculate the standard enthalpy of reaction.

I list their values below the corresponding formulas.

Note that the substances must be in their most stable states at 298 K and 1 bar, so water is listed as a liquid.

##color(white)(XXXXXXXXX)”CO”(“g”)color(white)(l) +color(white)(l) “H”_2″O”(“l”) →”CO”_2(“g”) +”H”_2(“g”)## ##ΔH_f^°(“kJ/mol”)color(white)(X) “-110.53″color(white)(XX) “-285.83″color(white)(XXl) “-393.51″color(white)(l)color(white)(XX)0##

##ΔH_”reaction”^° = sum(ΔH_f^°(“products”)) – sum(ΔH_f^°(“reactants”)) =” [1(-393.51) + 1(0) – 1(-110.53) – 1(-285.83)] kJ” =”2.85 kJ”##