Acid-base equilibria and acidity scales in ethylene glycol/water solvent mixtures : recommended reference-value pH-metric standards and ionization constants for o-phthalic acid at normal and subzero temperatures

The rising interest for acid/base behavior and related controls at subzero temps. prompted the present systematic work of pH-metric standardization in ethylene glycol/water solvent mixts. The recommended set of Ref. Value Stds. pHRVS was assessed to cover the ranges of current practical interest, i.e. from -10 to +45°C and up to 70 wt. per cent ethylene glycol. Since, contrary to most other solvent systems, for ethylene glycol and its mixts. with water the relevant data of autoprotolysis consts. are available, the relative lengths and comparabilities of pH scales in such mixts. with the current aq. pH scale are discussed.