Solvents consisting of 2-methoxyethanol (20, 50, and 80 mass % + water were chosen In a continuing study designed to shed light on the behavior of electrolytes in mixed media at temperatures extending below 0 °C. Electromotive-force measurements of celts with hydrogen and AgCI/Ag electrodes In the range from -10 to +37 °C, together with a recalculation of earlier data In the literature, yielded values of the standard potential of the HCI In the mixed solvents. A disagreement of literature values for the standard potential In the 80 mass % solvent was resolved. A further series of measurements of phosphate buffer solutions In 20 and 50 mass % 2-methoxyethanol + water led to values for the dissociation constant (p/f2) and associated thermodynamic function for dissociation of the primary phosphate Ion H2P04" In these mixed solvents.