ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Etalon buffer solutions in the mixed ethanol-water solvent

B. Cséfalvayová, E. Kozáková, and A. Thurzo

Czechoslovak Metrological Institute, CS-825 62 Bratislava

Abstract: The cells without liquid junction comprehending hydrogen electrode, silver/silver chloride electrode and electrolyte solutions consisting of the hydrogen phthalate or tetraborate buffer solution in mixed ethanol—water solvents were constructed. The mass fractions of alcohol in mixed solvents were w(C₂H₅OH) = 0.3; 0.5; 0.7. The values of EMF of these cells measured at 25 °C were used for calculating the conventional ра^*_H values of the buffer solutions which were recommended as primary etalon solutions of the first order for reproduction of the pH* value. Furthermore, the cells with liquid junction comprehending glass electrode,' silver/silver chloride electrode and electrolytes containing the oxalate, hydro­ gen succinate, and phosphate buffer solution in mixed ethanol—water solvents were also prepared. The values of EMF of the cells with liquid junction measured at 25 °C were used for calculating the pH* values of the corresponding buffer solutions in respect of the relation valid for the operational scale of pH*. These buffer solutions were recommended as secondary etalon solutions for reproduction of the pH* value. The buffer capacities and dilution values of all etalon solutions were determined.

Full paper in Portable Document Format: 404a537.pdf

Chemical Papers 40 (4) 537–541 (1986)