Reference value standards for pH measurements, and first ionization constants for o-phthalic acid, in 70 percent in weight ethylene glycol/water solvent mixtures at temperatures from 288.15 to 318.15 K

Ref. value stds., pHRVS, for 0.05 mol/kg potassium hydrogen phthalate (KHPh) ref. buffer solns. in 70% (wt./wt.) ethylene glycol/water mixed solvents at 288.15-318.15 K were detd. from reversible emf. measurements of the cell Pt|H2|KHPh + KCl|AgCl|Ag|Pt. The ancillary values of the first ionization const. of o-phthalic acid (H2Ph; benzene-1,2-dicarboxylic acid) in these mixed solvents were detd. from measurements of the reversible emf. of the cell Pt|H2Ph + KHPh + KCl|AgCl|Ag|Pt within the same of temp. range.