PH-METER CORRECTIONS FOR TITRATIONS IN MIXTURES OF WATER AND DIOXAN

New measurements are reported for the values of the correction term log UH (valid for μ = 0·1 M(NaCl) and 25° and 30°C) which must be added to pH-meter readings taken in solutions of aqueous dioxan of mole fraction n2=0-0·387 (0-75 per cent v/v) in order to give the true concentration of hydrogen ion. Earlier data have been corrected in the light of later measurements of mean ionic activity coefficients, γ±, for hydrochloric acid in aqueous-dioxan mixtures and values of log( 1 gg±) have been computed and tabulated by equal values of the argument n2. © 1968.