pH‐measurements in alcohol‐water mixtures. On the use of aqueous standard buffer solutions for calibration

To investigate the variation with alcohol‐percentage of the standard potential of glass electrodes of a wide range of types and manufactures, e.m.f.‐measurements have been made on cells of the type: glass electrode/standard buffer solution/saturated KCl‐solution (aq.)/Hg2Cl2‐Hg, using standard succinate buffer solutions in methanol‐water and ethanol‐water mixtures. An analysis is given of the accuracy of pH‐determinations in alcohol‐water mixtures, using both standard buffer solutions in the same solvent and aqueous standard buffer solutions for calibration.