Activity coefficients for aminoacid+electrolyte mixtures by using Pitzer equations: dl-α-amino- n-butyric acid in mixed electrolyte solutions of neutral, acid and alkaline pH values

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 466; no. 1; pp. 38 - 44
• Main Authors: Fernández-Mérida, Luis, Garcı́a-Garcı́a, Guillermo E., Raposo, Raquel R., Esteso, Miguel A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 14.05.1999; Elsevier Science
• Subjects: Activity coefficients; Chemical thermodynamics; Chemistry; dl-α-amino- n-butyric acid; Exact sciences and technology; General and physical chemistry; Mixed electrolyte solutions; Mixtures; Thermodynamic properties; Activity coefficients; Mixed electrolyte solutions; dl-α-amino- n-butyric acid; Water; Electrolyte solution; Activity coefficient; Electromotive force; Experimental study; Quaternary system; Hydrochloric acid; Racemic; α-Aminoacid; Hydrochlorides; Medium effect; Sodium Hydroxides; Organic salt; Carboxylate; pH; Aqueous solution; Thermodynamic properties; Sodium Chlorides
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/S0022-0728(99)00116-3

From emf values of galvanic cells of the types {Na-glass ∣ NaCl ( m B), HZ ± ( m A) ∣ AgCl (S) ∣ Ag}; {glass-H ∣ HCl ( m C=0.01 mol kg −1), HZ ± ( m A), NaCl ( m B) ∣ AgCl (S) ∣ Ag} and {glass-H ∣ HZ ± ( m A), NaZ ( m D=0.09982 mol kg −1), NaCl ( m B) ∣ AgCl (S) ∣ Ag} (where HZ ± stands for dl-α-amino- n-butyric acid), activity coefficients for NaCl and the aminoacid were determined, at various relative concentrations of both compounds, in the ionic strength range of 0.1–4 mol kg −1 and 298.15 K. Likewise, activity coefficients for both the pure aminoacid hydrochloride (up to 0.5 mol kg −1) and the sodium salt of the aminoacid (up to 0.1 mol kg −1) were also determined, together with the thermodynamic ionisation equilibrium constants for these latter compounds.