The dissolution of metals in dioxan-water solutions of hydrochloric acid (I) Aluminium
| Autor: | M. Allbutt, G. Tolley |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Journal of Applied Chemistry. 11:52-59 |
| ISSN: | 1934-998X 0021-8871 |
| DOI: | 10.1002/jctb.5010110203 |
| Popis: | The dissolution rates of aluminium in aqueous and dioxan solutions of hydrochloric acid have been determined by hydrogen evolution measurements. In aqueous HCl solutions the rate increases to a maximum, then decreases, paralleling progressive solution of the oxide film and emergence of a less reactive cubic etch relief. In water-rich solutions the rate is proportional to the partial vapour pressure of HCl, indicating a reaction dependent on the square of the mean ionic activity of HCl, i.e., aH+ × ac1−. In 100% dioxan, the reaction appears to proceed by a free-radical mechanism, inhibited by water. At critical solution compositions, determined by two particular values of the mole fraction ratio of water to HCl, there is an abrupt decrease in reaction rate. This apparent influence of water is explained by the necessity for the Al3+ ion to be fully hydrated before it can enter solution. |
| Databáze: | OpenAIRE |
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