Thermodynamics of the hydrolysis of TRISH+ in (water + 10 or + 20 mass per cent of acetonitrile) from 263.15 to 298.15 K

Article abstract of DOI:10.1016/0021-9614(87)90123-6

The standard potentials of (AgCl + 1/2H2 = Ag + HCl) in (water + 10 or + 20 mass per cent of acetonitrile) were used to determine the acidity constants of protonated tris(hydroxymethyl)aminomethane (TRISH+).Measurements were made at eight temperatures ranging from 263.15 to 298.15 K at 5 K intervals in cells without liquid junction.The molalities of TRISH+ ranged from 0.1 to 0.005 mol * kg^-1.The standard molar Gibbs free energy change Δ_rG_m⁰ of the reaction was calculated.From the values obtained in the literature for water and our values for the mixed solvents, the standard molar Gibbs free energy of transfer Δ_tG_m⁰ was also estimated.It was found that the hydrolysis of TRISH+ is less favored in the mixtures than in pure water.