Kinetics and mechanism of the reaction of gold(III) chloride complexes with formic acid
In this work, the results of kinetic studies of the redox reaction of gold(III) chloride complexes ([AuCl4]-) with formic acid, are presented. Obtained data suggest the complex character of the reaction which leads to the [AuCl2]- and [AuCl3(COOH)]- ions formation as intermediates. In the p...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Technical Faculty, Bor
2015-01-01
|
| Series: | Journal of Mining and Metallurgy. Section B: Metallurgy |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/1450-5339/2015/1450-53391500017P.pdf |
| Summary: | In this work, the results of kinetic studies of the redox reaction of
gold(III) chloride complexes ([AuCl4]-) with formic acid, are presented.
Obtained data suggest the complex character of the reaction which leads to
the [AuCl2]- and [AuCl3(COOH)]- ions formation as intermediates. In the pH
range over 2.5, the final product of the reaction is metallic gold. From the
analysis of kinetic data, the rate limiting step is found to be the gold
metallic phase formation. The stage of Au(III) reduction is relatively fast
with the second-order rate constant equal to 61.8 M-1s-1 at temperature 50ºC.
The rate of the studied reaction depends on the temperature, reactants
concentration and chloride ions concentration. As a result of the data
analysis, the scheme of the reaction path has been suggested. Also, the
values of enthalpy and entropy of activation for the reaction have been
determined. |
|---|---|
| ISSN: | 1450-5339 2217-7175 |