An amperometric study of the reactions of copper( I ) and copper( II ) oxides with barium peroxide in surfactant suspensions

A study was made of the amperometric titration of the reaction between barium peroxide and copper( I ) and copper( II ) oxides. It was shown that it was possible to titrate a solid with a solid in surfactant suspensions. The studies were made in aqueous and acetonitrile suspensions containing cationic surfactants. End points were obtained at molecular ratios of BaO 2 to CuO of 1 : 1, 1 : 3, and 1 : 5; and molecular ratios of BaO 2 to Cu 2 O of 1 : 1 and 2: 1. It was postulated that the reactions involving CuO were\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm BaO}_{\rm 2} + {\rm CuO} \to {\rm BaCuO}_{\rm 3}} \\ {{\rm BaO}_{\rm 2} + {\rm 3CuO} \to {\rm Cu}_{\rm 3} {\rm O}_{\rm 4} + {\rm BaO or BaCu}_{\rm 3} {\rm O}_{\rm 5}} \\ {{\rm BaO}_{\rm 2} + 5{\rm CuO} \to {\rm BaCu}_{\rm 5} {\rm O}_{\rm 7} {\rm or BaO} + {\rm Cu}_{\rm 5} {\rm O}_{\rm 6}} \\ \end{array} $$\end{document} The reactions involving Cu 2 O were postulated to be\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm BaO}_{\rm 2} + {\rm Cu}_{\rm 2} {\rm O} \to {\rm BaCu}_{\rm 2} {\rm O}_{\rm 3}} \\ {{\rm 2BaO}_{\rm 2} + {\rm Cu}_{\rm 2} {\rm O} \to {\rm Ba}_{\rm 2} {\rm Cu}_{\rm 2} {\rm O}_{\rm 5}} \\ \end{array} $$\end{document} .