Deuterium isotope effects on the ionization of the lower carboxylic acids in water and deuterium oxide

To facilitate the interpretation of isotope effects on the ionization of weak acids in water and deuterium oxide, comparison with a standard acid is proposed. It was postulated that the isotope effect on the dissociation constant of n-alkanoic acids (C3-C4) and of trimethylacetic acid should be a constant factor at constant temperature approximately equal to that for acetic acid. The postulate was verified by electrochemical measurements using a quinhydrone electrode. (N.D.H.)