## 3 Fe (s alpha) + 4 H2O (g) → Fe3O4 (s magnetite) + 4 H2 (g)

Back to reactions list

## Reaction Type:

Single displacement/Oxidation-reduction

## 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.

 Fe             Mass: g H2O            Mass: g or Gas Volume: L Fe3O4          Mass: g H2             Mass: g or Gas Volume: L Heat Released: kJ

## Enthalpy of Reaction

[1ΔHf(Fe3O4 (s magnetite)) + 4ΔHf(H2 (g))] - [3ΔHf(Fe (s alpha)) + 4ΔHf(H2O (g))]
[1(-1118.38) + 4(0)] - [3(0) + 4(-241.82)] = -151.1 kJ
-151.10 kJ     (exothermic)

## Entropy Change

[1ΔSf(Fe3O4 (s magnetite)) + 4ΔSf(H2 (g))] - [3ΔSf(Fe (s alpha)) + 4ΔSf(H2O (g))]
[1(146.44) + 4(130.59)] - [3(27.28) + 4(188.72)] = -167.92 J/K
-167.92 J/K     (decrease in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[1ΔGf(Fe3O4 (s magnetite)) + 4ΔGf(H2 (g))] - [3ΔGf(Fe (s alpha)) + 4ΔGf(H2O (g))]
[1(-1015.46) + 4(0)] - [3(0) + 4(-228.59)] = -101.1 kJ
-101.10 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-101.03 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

5.1634413233e+017
This process is favorable at 25°C.

## Reference(s):

Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change 4th ed.; McGraw-Hill: Boston, MA, 2006; p 127.
Kotz, John C. and Treichel, Paul. Chemistry & Chemical Reactivity 4th ed.; Thomson Brooks/Cole: Belmont, CA, 1999; p 173.
Kotz, John C., Treichel, Paul, and Weaver, Gabriela. Chemistry & Chemical Reactivity 6th ed.; Thomson Brooks/Cole: Belmont, CA, 2006; p 166.