Technical report. From Abstract : "The acidity of a solution of acid, HX, and salt, MX, is affected by both the concentration of X- and M+ owing to incomplete dissociation of the salt, MX. it was possible to increase the acidity of a solution of 2,6-di-tert-butylphenol - tetrabutylammonium 2,6-di-tert-butylphenolate relative to a dilute solution of tetrabutylammonium hydroxide by increasing the tetrabutylammonium bromide content. This indicates that the dissociation constant of the hydroxide base is sufficiently large that extensive dissociation occurs in dilute solutions. The addition of tetrabutylammonium bromide is therefore recommended as a general method for increasing the acidity and improving the titration characteristics of extremely weak acids."