| Autor: |
C. E. Roberson, John David Hem, Carol J. Lind |
| Rok vydání: |
1985 |
| Předmět: |
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| Zdroj: |
Geochimica et Cosmochimica Acta. 49:801-810 |
| ISSN: |
0016-7037 |
| DOI: |
10.1016/0016-7037(85)90173-5 |
| Popis: |
A precipitate of cobalt oxyhydroxides formed by bubbling oxygen through a dilute solution of Co(NO3)2 held at pH 9.0 and 25°C was aged for 23 months in contact with the original solution, with access to atmospheric oxygen. Co3O4 and CoOOH were identified in the precipitate by X-ray diffraction. Chemical equilibria involving these solids were evaluated by measurements of solution pH and Co2+ activities and by redox potential measurements and gave a ΔG coOOH 0 of −92.3 ± 0.5 kcal/mole . This value and other thermodynamic data show relative feasibility of hypothetical reaction steps and changes in reaction paths during automated coprecipitation titrations and subsequent aging of a precipitate that finally contained βMnOOH, MnO2 (birnessite) and CoOOH. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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