Enthalpies of solution of some aromatic sulphonic acids and of some aminosulphonic acids

Abstract The molar enthalpies of solution at 298.15 K of several aromatic sulphonic acids and of some aminosulphonic acids were measured in water, in aqueous acid, and in aqueous alkali. Molar enthalpies of ionization in aqueous solution were derived for orthanilic acid (11.86 ± 0.53 kJ mol −1 ), metalinic acid (20.79 ± 2.1 kJ mol −1 ), sulphanilic acid (17.91 ± 0.63 kJ mol −1 ), aminomethanesulphonic acid (29.14 ± 0.32 kJ mol −1 ) and taurine (43.39 ± 0.65 kJ mol −1 ).