Thermodynamic quantities for the dissociation equilibria of biologically important compounds. 3. The dissociations of the magnesium salts of phosphoric acid, glucose 1-phosphoric acid and glycerol 2-phosphoric acid

Abstract

The thermodynamic dissociation constants of magnesium phosphate, magnesium glucose 1-phosphate and magnesium glycerol 2-phosphate on the molal scale were measured at 10[degree] intervals from 10[degree] to 50[degree] using H and silver-silver chloride electrodes in cells without liquid junction. From these measurements were calculated the standard free energy, heat content, entropy and heat capacity for the ionizations at 25 and 37[degree]. The magnitude and sources of error are discussed. Sufficient information was given for the dissociations of these salts to be considered quantitatively in any kinetic or other study of phosphate, glucose 1-phosphate or glycerol 2-phosphate in the presence of Mg ions.