The data regarding the protonation of 22-(mono-, di-, ..., penta-) carboxylic acids in aqueous tetraethylammonium iodide at different ionic strengths 0 < I less than or equal to 1 mol dm(-3), and temperatures 5 less than or equal to T less than or equal to 55 degrees C, have been re-examined. Dependence on ionic strength was taken into account by using different models (Debye-Huckel type, Fitter and Bromley equations). The parameters obtained for these equations were found to be a simple function of acid anion charge (and temperature) and are not, as a first approximation, dependent on the type of acid considered.