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Heat of Formation of O2–

Gaffney, Edward S. and Ahrens, Thomas J. (1969) Heat of Formation of O2–. Journal of Chemical Physics, 51 (3). pp. 1088-1091. ISSN 0021-9606. http://resolver.caltech.edu/CaltechAUTHORS:GAFjcp69

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Abstract

A series of Born–Mayer-type calculations are used to calculate the lattice energies of simple oxides (MgO, BeO, CaO, and ZnO). Repulsion and other non-Coulombic contributions to the lattice energy are obtained using thermodynamic and recent ultrasonic data for the bulk moduli and the isothermal pressure and temperature derivatives of the elastic constants. Using thermochemical data for the heat of formation of MgO, CaO, and BeO and their cations, the heat of formation of O2–, DeltaHf°(O2–), is calculated to be 197 ± 5 kcal/mole. Using the largest value of DeltaHf°(O2–), obtained for MgO, presumably the most ionic of the crystals treated, a value of 202.3 kcal/mole is obtained. These values are believed to be more accurate than earlier values given by Morris and by Huggins and Sakamoto who obtained 210 ± 6 and 221 ± 15 kcal/mole. The anomalously low value calculated for DeltaHf°(O2–) for ZnO is believed to result from a substantial covalent contribution in the Zn[Single Bond]O bond in this oxide.


Item Type:Article
Additional Information:©1969 American Institute of Physics (Received 20 February 1969) We have profited from discussion of these calculations with D. L. Anderson and W. B. Kamb. This research was in part supported by Defense Atomic Support Agency Contract DASA 01-68-C-0069. Contribution No. 1605, Division of Geology and Planetary Sciences. California Institute of Technology. Pasadena, Calif.
Record Number:CaltechAUTHORS:GAFjcp69
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:GAFjcp69
Alternative URL:http://dx.doi.org/10.1063/1.1672107
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4877
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:12 Sep 2006
Last Modified:26 Dec 2012 09:02

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