Standard electromotive force of the H2-AgCl;Ag cell in 30, 40, and 50 mass% glycerol/water from −20 to 25 °C: pK2 and pH values for a standard “Mops” buffer in 50 mass% glycerol/water |
| |
Authors: | Rabindra N Roy James J Gibbons Timothy McGinnis Ray Woodmansee |
| |
Abstract: | Data are presented regarding the establishment of the pH (designated pH*) of a standard buffer solution suitable as a pH reference in 50 mass% glycerol/water mixtures at temperatures ranging from −20 to 25 °C. The buffer material selected was the ampholyte Mops (3-N-morpholino)-propane sulfonic acid], and the reference standard consists of equal molal amounts of Mops and its sodium salt. The assignment of pH* values is based on measurements of the electromotive force (emf) of cells without liquid junction of the type: Pt;H2(g,1 atm) ¦ Mops, Na Mopsate, NaCl ¦ AgCl;Ag and the pH* was derived from a determination of K2, the equilibrium constant for the dissociation process (Mops)±/ah (Mopsate)− + H +. The standard emf of the silver-silver chloride electrode in 30, 40, and 50 mass% glycerol/water mixtures was determined from emf measurements of the cell at subzero temperatures with HCl solutions replacing the buffer-chloride mixtures. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|