Potentiometric titrations in non-aqueous solution : Anomalous behaviour of weak oxygen acids in inert and weakly basic solvents

A number of carboxylic acids, phenols and certain related compounds have been found to yield anomalous titration curves in inert and weakly basic solvents. Amongst the effects observed are reproducible potential rises in the region of half-neutralization and irrcproducible potential drops often at stages of the titration corresponding to simple fractions of total neutralization.An investigation has been made into the influence of the basic and amphiprotic character of the solvents, of steric hindrance in the acid molecules, of substitution of —OH (in phenols) by —SH, and of —COOH (in carboxylic acids) by —SOOH, and of the type of electrodes on the occurrence and type of anomalies.These, and the other observed anomalies are interpreted.