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Iron Species and their Thermodynamic Data

Pure species considered

Species

Go (298 K)

So(298 K)

A

B x 103

C x 10-5

(Jmol-1)

(Jmol-1)

O2 0 205 29.96 4.184 -1.674
H2 0 131 27.28 3.263 0.502
H2O -237000 69.9 75.27 0 0
Fe 0 27.1 12.72 31.71 -2.51
Fe3O4 -1,020,000 146 91.55 201.67 0
Fe2O3 -742,000 87.3 98.28 77.82 -14.85
Fe(OH)2 -493,000 92.4 96.3 0 0
Fe(OH)3 -714,000 96.1 105 0 0

Soluble species considered

Species Go (298 K) So (298 K) o (298 K) a b
(Jmol-1) (Jmol-1) (Jmol-1)
H+ 0 0 -20.9 0.065 -0.005
Fe(OH)2(sln) -449,000 38 38 0.13 -0.0017
Fe(OH)3(sln) -661,000 75.2 75.2 0.13 -0.0017
FeOH+ -274,000 -29.3 -50.2 0.13 -0.0017
Fe(OH)2+ -459,000 -29.3 -50.2 0.13 -0.0017
Fe2+ -92,200 -107 -149 0.13 -0.0017
FeOH2+ -242,000 -105 -147 0.13 -0.0017
Fe3+ -17,800 -279 -342 0.13 -0.0017
Fe(OH)3- -621,000 41.8 62.7 -0.37 0.0055
Fe(OH)4- -843,000 25.1 46 -0.37 0.0055
FeO42- -467,000 37.6 79.5 -0.37 0.0055

See also: Equilibrium reactions of iron in water, Iron corrosion products, Iron species and their thermodynamic data, Pourbaix diagram of iron, Rust chemistry, Rust converters, Steel corrosion