## CO2 (g) + 1 H2 (g) → CH4 (g methane) + H2O (ℓ)

Back to reactions list

## Stoichiometry

Enter a mass or volume in one of the boxes below. Upon hitting submit, the stoichiometric equivalents will be calculated for the remaining reactants and products. All gases are assumed to be at STP.

 Heat Added: kJ CO2            Mass: g or Gas Volume: L H2             Mass: g or Gas Volume: L CH4            Mass: g H2O            Mass: g

## Enthalpy of Reaction

[1ΔHf(CH4 (g methane)) + 1ΔHf(H2O (ℓ))] - [1ΔHf(CO2 (g)) + 1ΔHf(H2 (g))]
[1(-74.85) + 1(-285.83)] - [1(-393.51) + 1(0)] = 32.83 kJ
32.83 kJ     (endothermic)

## Entropy Change

[1ΔSf(CH4 (g methane)) + 1ΔSf(H2O (ℓ))] - [1ΔSf(CO2 (g)) + 1ΔSf(H2 (g))]
[1(186.27) + 1(69.91)] - [1(213.68) + 1(130.59)] = -88.09 J/K
-88.09 J/K     (decrease in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[1ΔGf(CH4 (g methane)) + 1ΔGf(H2O (ℓ))] - [1ΔGf(CO2 (g)) + 1ΔGf(H2 (g))]
[1(-50.84) + 1(-237.18)] - [1(-394.38) + 1(0)] = 106.36 kJ
106.36 kJ     (nonspontaneous)

From ΔG = ΔH - TΔS:
59.09 kJ     (nonspontaneous)

## Equilibrium Constant, K (at 298.15 K)

2.320050013e-019
This process is not favorable at 25°C.

## Reference(s):

Atkins, Jones, and Laverman. Chemical Principles 6th ed.; W.H. Freeman and Company: New York, NY, 2013; p F94.