Paper
Thermodynamic Study of the Second-Stage Dissociation of 2-Aminoethanesulfonic Acid (Taurine) in Water at Different Ionic Strength and in Dioxane-Water Media
- Authors:
- Mohamed Magdy Khalil; Rehab Khaled Mahmoud; Saif Elden Babiker
- Abstract
- The second-stage dissociation constant pK2 of 2-Aminoethanesulfonic acid (taurine) was determined in aqueous solution at different ionic strengths and different temperatures, using pH- metric technique. The thermodynamic quantities (ΔG°, ΔH°, and ΔS°) were studied and discussed. The protonation equilibria for the Taurine in nonaqueous solutions were studied by pH-potentiometry. The dissociation constants, pKa, of taurine and the thermodynamic parameters for the successive and overall protonation processes of taurine were derived at different temperatures in three different mixtures of water and dioxane (mole fractions of dioxane were 0.083, 0.174 and 0.33). Titrations were also carried out in (water + dioxane) with ionic strengths of 0.15, 0.20 and 0.25 mol・dm−3 NaNO3, and the resulting dissociation constants are reported in this paper. A detailed thermodynamic analysis of the effects of organic solvent, dioxane, temperature and ionic strength on the protonation processes of taurine is presented and discussed to determine the factors that control these processes.
- Keywords
- Protonation Constants; Taurine; Potentiometry; Solution Studies
- StartPage
- 49
- EndPage
- 57
- Doi