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Abstract: The electric conductance of solutions of sulfuric, oxalic, benzoic, and salicylic acid (up to 0.02M) in dioxane–water mixed solvents (90% and 93% dioxane by mass) has been studied in the presence and absence of TiO2 and Al2O3 (0.5–5% by mass). TiO2 and Al2O3 enhanced the conductance of solutions of organic acids in aqueous dioxane. The conductance is interpreted in terms of adsorption of acid in molecular form, dissolution of ceramic oxides in form of anionic complexes, and leaching of acidic impurities from ceramic oxides. [Copyright &y& Elsevier]

Abstract: In this work, densities of binary mixtures of {water+formamide (FM), or + N,N-dimethylformamide (DMF), or +dimethylsulfoxide (DMSO), or + N,N-dimethylacetamide (DMA), or +1,4-dioxane}, have been determined under atmospheric pressure as a function of composition and temperature using a vibrating-tube densimeter. The temperatures studied were T =(288.15, 293.15, 298.15, and 303.15) K. The excess molar volumes , calculated from density data, are negative over the whole mole fraction range for the temperature range studied. The values have been fitted to Redlich–Kister polynomial equation and others volumetric properties were calculated. The partial molar volumes at infinite dilution of each component have been determined using three different methods. [Copyright &y& Elsevier]