PH the Hammett acidity function, "H", has been developed in connection with superacids. The concept of "unified pH scale" has been developed on the basis of the absolute chemical potential of the proton. This model uses the Lewis acid–base definition. This scale applies to liquids, gases and even solids. In 2010, a new "unified absolute pH scale" has been proposed that would allow various pH ranges across different solutions to use a common proton reference standard. Pure water is neutral. When an acid is dissolved in water, the pH will be less than 7 (25 °C). When a base, or alkali,
Glyoxylic acid "monohydrate." This geminal diol exists in equilibrium with the dimeric hemiacetal in solution: Henry's law constant of glyoxylic acid is K = 1.09 × 10 × exp[(40.0 × 10/R) × (1/T − 1/298)]. The conjugate base of glyoxylic acid is known as glyoxylate and is the form that the compound exists in solution at neutral pH. Glyoxylate is the byproduct of the amidation process in biosynthesis of several amidated peptides. Historically glyoxylic acid was prepared from oxalic acid electrosynthetically: In organic synthesis, lead dioxide anodes were applied for the production of glyoxylic acid from oxalic acid in a sulfuric acid