Potentiometrische Titration von Sulfat, Barium und Strontium mit Hilfe einer bleisensitiven Elektrode

Zusammenfassung Die bleisensitive Elektrode der Fa. Orion spricht neben Bleiionen auch auf Sulfationen an. Dies ermöglicht die potentiometrische Titration von Sulfat mit Bariumperchlorat sowie die Titration von Barium und Strontium mit Natriumsulfat. Der günstigste pH-Bereich liegt zwischen 5 und 7. Titriermedium sind Dioxan-Wasser-Gemische. Die Verfahren sind sehr empfindlich und erlauben in allen Fällen die Titration bis herab zu 5·10^–4 mMol.Anwendungsbeispiele für die Bestimmung von Schwefel in organischen Verbindungen nach Schöniger- oder Wickbold-Verbrennung sind angegeben.

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Potentiometric titration of sulphate, barium and strontium by means of a lead-sensitive electrode

The Orion lead electrode was found to be responsive not only to lead ions but to sulphate ions, too. This offers possibilities to titrate sulphate with barium perchlorate and reversely barium and strontium with sodium sulphate. The useful pH range is 5–7. Dioxan-water mixtures serve as solvents. The described methods are highly sensitive and allow determinations down to 5×10^–4 millimoles.Examples are given for the determination of sulphur in organic samples after combustion according to Schöniger or Wickbold.

     

Reversible S0/MgSx Redox Chemistry in a MgTFSI2/MgCl2/DME Electrolyte for Rechargeable Mg/S Batteries

The redox chemistry of magnesium and its application in rechargeable Mg batteries has received increasing attention owing to the unique benefits of Mg metal electrodes, namely high reversibility without dendrite formation, low reduction potentials, and high specific capacities. The Mg/S couple is of particular interest owing to its high energy density and low cost. Previous reports have confirmed the feasibility of a rechargeable Mg/S battery; however, only limited cycling stability was achieved, and the complicated procedure for the preparation of the electrolytes has significantly compromised the benefits of Mg/S chemistry and hindered the development of Mg/S batteries. Herein, we report the development of the first rechargeable Mg/S battery with a MgTFSI₂/MgCl₂/DME electrolyte (DME=1,2‐dimethoxyethane, TFSI=bis(trifluoromethanesulfonyl)imide) and realize the best cycling stability among all reported Mg/S batteries by suppressing polysulfide dissolution. Mechanistic studies show that the battery works via S⁰/MgS_x redox processes and that the large voltage hysteresis is mainly due to the Mg anode overpotential.