2926.     ---------------.  [RUFF, O., AND GERSTEN, E.]  [Iron Carbide.]  Ber. deut. chem. Gesell., vol. 46, 1913, pp. 394-400; Chem. Abs., vol. 7, 1913, p. 1848.

        Molecular heat of formation of Fe₃C was previously found to be -15.1 cal.  Recalculation by Le Chatelier’s method revealed the heat of oxidation of FeO to 1/3 Fe₃O₄ to be 28.6±1.8, while Le Chatelier obtained 25.7.  Revised calculations gave the following results:  Molecular heat of formation of Fe₃O₄ (Fe=55.8)=267.1±0.2 cal.; of FeO=60.4±1.8 cal.; of Fe₃C from a-Fe and graphite= -15.3±0.2 cal. (See abs. 2924.)