763.    EASTMAN, E. D., AND EVANS, R. M.  Equilibria Involving the Oxides of Iron.  Jour. Am. Chem. Soc., vol. 46, 1924, pp. 888-903; Chem. Abs., vol. 18, 1924, p. 1418.

     Compositions of the gas phase in equilibrium with solid phases varying in average composition between pure Fe and Fe₃O₄ have been determined at 772° in the system Fe : H₂ : O₂.  The results indicate the existence at this temperature of solid solutions in the composition ranges 0-5% O₂, 20-24% O₂, and above about 27% O₂.  Equilibrium constants in the divariant equilibrium in this system represented by the equations, FeO+H₂=Fe+H₂O, and Fe₃O₄+H₂=3FeO+H₂O have been determined between about 657° and 1,025°; and a series of measurements has been made of the constant of the divariant equilibrium Fe₃O₄+CO=3FeO+CO₂, between 816° and 1,039°.  From the values obtained for the equilibrium constants, the equilibrium constant of the water gas reaction has been calculated.  The values of I in the free-energy equation, calculated from the values of this constant, show a satisfactory constancy.  Corrections to the free-energy data relating to CO and CO₂ have been made on the basis of the new results.

     EASTWOOD, A. H.  See abs. 1742.

     EBERT, W.  See abs. 3052, 3053.