Thermodynamic study of (NaBr + L-Serine + Water) ternary system based on potentiometric measurements at T = (298.2, 308.2 and 318.2) K

Abstract

In this investigation, the results of the modeling and determination of thermodynamic properties the NaBr + L-Serine + water ternary system using the potentiometric technique were presented. The electromotive force was obtained on the electrochemical cell of the type: Na − ISE|NaBr(mNaBr), L-Serine(wt)%, H2O(1- wt)%|Br − ISE in water and L-Serine mixtures (wL-Serine /wwater+L-Serine = 0, 2.5, 5, 7.5, and 10 mass fractions percent) and the ionic strength varying from 0.0107 to 3.1103 mol.kg−1 at T = (298.2, 308.2 and 318.2) K. For experimental data correlation, Extended Debye–Hückel, Pitzer and Pitzer–Simonson–Clegg equations were implemented. Then, using these models, properties of electrolyte solutions such as the mean activity coefficients, the excess Gibbs free energy, the osmotic coefficients, the solvent activity, the excess Entropy and the excess Enthalpy were determined. Also, the activity coefficient of L-Serine and salt effect was investigated. The obtained results indicated that the Pitzer and Pitzer–Simonson–Clegg model can reproduce in more accurately the corresponding data correlation.