UBC Theses and Dissertations
Carbon monoxide reduction of aqueous silver acetate McAndrew, Robert Thomson
The kinetics of the carbon monoxide reduction of silver perchlorate in sodium acetate - acetic acid buffered aqueous solution were studied between 60 and 110°C by following the pressure decrease in a closed system. The reduction occurs homogeneously in the liquid phase by two parallel reaction paths, one of which is independent of pH. The second path is favoured by increased pH and has both an acetate-independent and an acetate-dependent component. The observed kinetics are consistent with the formation of intermediate complexes by the insertion of a carbon monoxide molecule between a silver ion and a co-ordinated oxygen-donating base (e.g. OAc[superscript -], H₂O) according to the following mechanism: [Chemical formulae omitted] Silver-acetate complexes are about a factor of three more reactive than hydrated silver ions in the pH-dependent reaction. This enhanced reactivity is attributed to stabilization by the basic acetate anion of the proton released in the reduction process. The effect of increased pH on the reduction rate is much greater than the specific effects associated with silver-acetate complexing.
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