“…The activity postulate itself has led to estimates of degenerate activity coefficients of single ions, of liquid junction potentials and of ion solvation energies. In a manner resembling the use of acidity functions, the Y0-values have been used to investigate the mechanism of the specific acid-catalyzed rearrangement of phenylpropenylcarbinol (105), of the racemization of 3-p-menthene (163) and of the hydrolysis of substituted o-benzoate esters (161).…”