Determination of protonation constants of some 3-alkyl(aryl)-4-(p-t-butyl(benzyl/benzyliden)amino)-4,5-dihydro-1H-1,2,4-triazole-5-one derivatives in ethanol–water mixtures

Stoichiometric protonation constants of some 3-alkyl(aryl)-4-(p-t-butyl(benzyl/benzyliden)amino)-4,5-dihydro-1H-1,2,4-triazole-5-one derivatives were determined potentiometrically in 50% (v/v) ethanol-water mixtures at 25 oC with an ionic strength of 0.10 M. The calculation of the stoichiometric protonation constants was carried out using a PKAS computer program. The effect of solvents composition on the stoichiometric protonation constants are discussed. KEY WORDS: Ethanol-water mixtures, Stoichiometric protonation constants, Potentiometry Bull. Chem. Soc. Ethiop. 2010, 24(2), 185-192.